WO2024165230A1 - Modified poly(hydroxyurethanes) (phus) - Google Patents

Abstract

The invention relates to a process for preparing a non-crosslinked modified polyhydroxyurethane (PHU) via intramolecular cyclization reactions comprising the step of: reacting a starting non-modified PHU compound, having repeating units, containing two proximate hydroxyl groups separated by 2 to 7 atoms, with a chemical capable of ring formation with the hydroxyl functionalities, selected from the group consisting of an aldehyde compound, ketone compound and/or boronic acid compound, in the presence of a Bronsted acid type catalyst for aldehyde and/or ketone at a temperature range of from 40°C to 100°C, during 24h-96h, or optional presence of a Bronsted base type catalyst for the boronic acid, at a temperature range of from 25°C to 100°C, during 05h-96h, a solvent, and using a stoichiometric ratio of said aldehyde, ketone, boronic acid compounds to the repeating unit of starting non-modified PHU compound of between 0.1:1 and 100:1 by mol.

Description

Description

Modified poly(hydroxyurethanes) (PHUs)

The invention relates to the field of non-isocyanate polyurethanes (NIPII). More specifically the invention relates to a process for modifying NIPII to provide them with specific targeted properties.

Polyurethanes (Pll) are produced by reacting diisocyanates with polyols in the presence of a catalyst or without it, or upon exposure to ultraviolet light. Common catalysts include tertiary amines, such as triethylamine (TEA), tetrametylethylenediamine (TE), pentamethyldiethylenetriamine (DT), 1 ,5,7- triazobicyclo[4.4.0]dec-5-ene (TBD), 1 ,4-diazabicyclo[2.2.2]octane (DABCO), etc. or metallic soaps, such as dibutyltin dilaurate or tin(ll) 2-ethylhexanoate. The stoichiometry of the starting materials must be carefully controlled as excess isocyanate can trimerize, leading to the formation of rigid polyisocyanurates. The moisture content should be also managed as the traces of water start to convert the isocyanates to amines, while the latter immediately react to form urea linkages with simultaneous release of gaseous CO₂. As a result, the polymer usually has a highly crosslinked molecular structure, resulting in a thermosetting material which does not melt on heating; although some thermoplastic polyurethanes are also produced.

Use of isocyanate-based monomers in PU synthesis indeed raises severe health concerns. Regular isocyanates are actually synthesized using phosgene, a highly reactive and toxic gas. Isocyanates themselves are very toxic and powerful irritants to the mucous membranes of the eyes as well as to gastrointestinal and respiratory tracts. Direct skin contact can also cause significant inflammation. Isocyanates are known to cause chronical asthma issues and can also sensitize workers, making them subject to severe asthma attacks if they are exposed again. Moreover, PU synthesis most often requires the use of a catalyst, typically organotin compounds, such as dibutyltin dilaurate or tin(ll) 2-ethylhexanoate. The success of this catalyst is related to its high activity at low loading. However, it can be hardly removed from the final polymers. The presence of residual catalyst in PUs causes detrimental effects on their aging. In addition, some studies suggested the possibility of tissue function endangerment through slow penetration of the catalyst into the blood circulation system, which questions the usage of tin-derived PUs in biomedical and food contact applications. Finally, as Plls are usually synthesized in organic solvents, for a use in applications such as coatings, paints, inks and adhesives, this necessitates the evaporation of a large amount of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) in the atmosphere. Exposure to VOCs is known to provoke health effects, such as headaches, dizziness, irritation, cancer, and the like. Thus, researchers in industry and in academia have put significant efforts in the past years to find synthetic alternatives to Plls, involving non-toxic reagents.

One of these alternatives consists in the synthesis of non-isocyanate polyurethanes, referred to as NIPUs. One can distinguish seven synthetic pathways to NIPUs, including (1 ) the step-growth polymerization of bis-cyclic carbonates and diamines, (2) the step-growth polymerization of linear activated dicarbonates and diamines, (3) the step-growth polymerization of linear activated bis-carbamates and diols, (4) the stepgrowth polymerization of alkylene bis-ureas and diepoxides, (5) the self polycondensation of bis-hydroxyalkylcarbamates, (6) the self polycondensation of AB- type synthons (R’-O-CO-NH-R-OH, for example), and (7) the ring-opening polymerization of cyclic carbamates. NIPII has attracted increasing attention because of the much “greener” synthetic routes not involving highly toxic compounds and their potential to substitute conventional Plls. Their potential technological applications include chemical-resistant coating, sealants, foam, etc. (Jing Guan et al, Progress in Study of Non-lsocyanate Polyurethane, Ind. Eng. Chem. Res. 2011 , 50, 11 , 6517- 6527; Amaury Bossion, PhD thesis, december 18, 2018, “New challenges in the synthesis of non-isocyanate polyurethanes”).

US 2011/0288230 A) discloses a method for preparing a compound, an oligomer or a polymer (U) having at least one urethane group and at least one hydroxyl group, said method employing: a) at least one compound having a cyclic carbonate functional group and at least one hydroxyl functional group, the oxygen atom of at least one hydroxyl functional group being bonded to the carbon atom of the carbonyl of said cyclic carbonate by from 3 to 5 atoms; b) at least one compound carrying at least one linear carbonate functional group; c) at least one compound carrying at least one primary or secondary amine functional group, preferably carrying at least two primary and/or secondary amine functional groups; and d) optionally at least one catalyst. The most common type of NIPUs are the polyhydroxyurethanes (PHUs) which contain at least two secondary hydroxyl groups in each repeating unit as the consequence of their synthesis. These materials suffer from being highly hydrophilic, impairing their mechanical properties, i.e. there is a high dependence of mechanical properties on humidity. In addition, this tendency to absorb moisture can result in in hydrolysis when the materials are heated leading to the loss of the molecular weight and significantly lowering of mechanical properties and physical stability in humid atmosphere. Moreover, the absorbed water due to the presence of high amounts of hydroxyl groups can act as the plasticizer significantly reducing the glass transition temperature of PHUs and drastically decreasing the mechanical properties on storage or in humid atmosphere.

The chemical modification of PHUs represents a known means of altering properties and potentially reducing moisture sensitivity as well. The literature has reported that the mechanical properties of the modified PHUs are usually lower compared to unmodified ones due, for example, the introduction of polymeric side chains or short- chained substituents that results in loss of intermolecular hydrogen bonding.

In general, the modification of conventional PUs with formaldehyde or formaldehyde precursors (for example, trioxane, paraformaldehyde, methylal, methylol acetone, dimethylol acetone, trimethylol acetone, tetramethylol acetone, methylol malonic ester, methylol nitro-malonic ester, hydroxymethyl nitropropane, S-hydroxymethyl-p- tertiary butyl thiophenol, tris-hydroxymethyl phosphine, diphenylbis-hydroxymethyl phosphonium chloride, hexamethylene tetramine as well as methylol compounds, methylol ethers and methylol acetates of urea, ethylene urea, methylene diurea, diurea methylene ether, hexamethylene diurea, acetylene diurea, hydrazodicarbonamide, acrylamide and methacrylamide, as well as homopolymers and copolymers of these compounds, urones, e.g. tetra-hydro(1 ,3,5- oxydiazinone-(4), dimethyl-bis-ureidoethyl ammonium compounds, melamine, dicyandiamine, lauroylamide, stearylamide, 4-5 - dihydroxy-tetrahydroimidazolone- 2 polymethylol polyvinyl alcohol, polyvinyl alcohol polyformal and the like) is possible and could also be applied to PHUs, as disclosed in US 3,384,606, but will result in unwanted crosslinking which negatively impacts processability (compression molding, extrusion, etc.). Modification of the hydroxyls in PHUs with isocyanate-functional reagents is likewise obvious, but this defeats the purpose of producing the PHUs via a non-isocyanate route, risks unwanted crosslinking (except in the case of monoisocyanates), and creates substantial hazards as well. Still another option is the acylation of PHU hydroxyls with various mono- or polyfunctional acid chlorides, acid anhydrides, etc [(a) Beniah, G., Heath, W. H. & Torkelson, J. M. J. Polym. Sci. Part A Polym. Chem. 55, 3347-3351 (2017); (b) Ochiai, B., Inoue, S. & Endo, T. J. Polym. Sci. Part A Polym. Chem. 43, 6613-6618 (2005); (c) Matsukizono, H. & Endo, T. RSC Adv. 5, 71360- 71369 (2015).]. As in the isocyanate case, unwanted crosslinking will occur with polyfunctional acylation reagents, and while monofunctional acylation reagents are provide some of the desired performance enhancements, the modification process is not convenient (involving hazardous I corrosive I toxic materials) and not readily amenable to PHUs containing closely spaced hydroxyls due to steric effects. Silylation has been reported [Ochiai, B., Inoue, S. & Endo, T. J. Polym. Sci. Part A Polym. Chem. 43, 6613-6618 (2005)] as yet another approach to the modification of hydroxyls in PHUs but generates alkoxysilyl groups with significant moisture sensitivity. It should also be noted that none of these approaches utilize intramolecular cyclization reactions as the means of modification. Finally, emphasizing the impracticality of these approaches, it is notable that, while PHUs have been described in the research literature for decades, and all of the above modification approaches are likewise well- known, that there is not a single example of a commercially produced modified PHU on the market.

Accordingly, there is a need to provide non-crosslinked modified PHUs that (i) are presenting reduced water sensitivity (or improved hydrophobicity), (ii) are retaining the mechanical properties of linear unmodified PHUs, and/or (iii) are presenting high tolerance towards the introduced functionality allowing then a large selection of new properties, such as luminescence, fluorescence, gas sorption ability, hydrophobicity, UV curability, etc.

The invention relates to a process for preparing a modified linear polyhydroxyurethane (PHU), via intramolecular cyclization reactions, comprising the step of: reacting a starting non-modified PHU compound, having repeating units, containing two proximate hydroxyl groups separated by 2 to 7 atoms, of formula (I)

wherein

- n is integer of from 5 to 150, preferably 20 to 150, more preferably 50 to 150;

- R” is derived from a diamine reagent and is comprised of one or more of the following entities selected from the group consisting of: linear or branched aliphatic, cycloaliphatic and aromatic moieties, oligomeric/(co-)polymeric species, such as poly(alkylene oxides), poly(siloxanes), poly(dienes), poly(olefins), poly(amides), and (co-)polymeric species in the form of am ineterminated oligomers;

- R’” is derived from a dicarbonate reagent which consists of terminal carbonate groups, and is comprised of one or more of the following entities selected from the group consisting: linear or branched aliphatic, cycloaliphatic, and aromatic moieties; and additionally, that contains at least 2 hydroxyl functionalities (-OH), said hydroxyl functionalities being separated by no more than 7 atoms; and presenting a molecular weight of no more than 400 g/mol; with a chemical capable of ring formation with the hydroxyl functionalities, selected from the group consisting of an aldehyde compound of formula (II), ketone compound of formula (III) and boronic acid compound of formula (IV)

in the presence of a Bronsted acid type catalyst, and a solvent, and when using compound (II) and/or compound (III), in a stoichiometric ratio of to the repeating unit of polymer (I) of between 0.1 :1 and 100:1 by mol, at a temperature range of from 40°C to 100°C, during 24h-96h, or without any catalyst or in the presence of a Bronsted base type catalyst, and a solvent, and when using the compound (IV) in a stoichiometric ratio to the repeating unit of polymer (I) of between 0.1 :1 and 100:1 by mol, at a temperature range of from 25°C to 100°C, during 0.5h-96h, wherein

- R, R’ are, independently, selected from the group consisting of a linear or branched C-I-C-IQ alkyl or alkoxy group; a linear or branched C₂-C-i₀ alkenyl or alkylenoxy group; a linear or branched C₂-C₁₀ alkynyl group; a cyclo(C₃-C₆ alkyl) group, said groups optionally containing one or more hetero atoms; a heterocyclo(C₃-C₆ alkyl) group, wherein the hetero atom is selected from N, S, F and O; at least one linear or branched C-i-C₆ alkyl group, C₂-C₆ alkenyl or alkylenoxy group, a linear or branched C₂-C₆ alkynyl group, (CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, -(CH₂)_m-CF₃ group, -CH₂-(CF₂)_m-CF₃ group, o-, m-, p- substituted or unsubstituted phenyl group, polycyclic aromatic (PAH), heteroaromatic hydrocarbon and a keto heteroaromatic hydrocarbon, wherein m is of from 0 to 6.

The Applicant has shown that the modified linear poly(hydroxyurethanes) (PHUs) of the invention are, in the context of the invention, aldehyde modified PHUs, ketone modified PHUs or boronic acid modified PHUs and are then not crosslinked. Linear (modified PHUs) and “not-crosslinked” have the same meaning.

Advantageously, the process is leading to modified poly(hydroxyurethanes) (PHUs) which are, for example, presenting a non-limitative linear structure of formula (V) and/or a cycloaliphatic structure of formula (VI), selected preferably from the group consisting of

The process of the invention may in some other words result in modified non-cross- linked PHll(s) (aldehyde modified PHll(s), ketone modified PHll(s) and/or boronic acid modified PHll(s)) by forming a ring through the reaction of two proximate hydroxyl groups, i.e. separated by 2 to 7 atoms, preferably 2 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, where the substructure O-X-O is formed, where the 0 atom is derived from approximate hydroxyls and X represents a single atom coming from the chemical capable of ring formation with the hydroxyl functionalities, here also named modification agent. The process then involves intramolecular cyclization of adjacent hydroxyl groups in the specific PHUs with an aldehyde compound of formula (II), ketone compound of formula (III) and/or boronic acid compound of formula (IV).

In some preferable embodiments, the starting non-modified PHU compound of formula (I) may advantageously be selected to lead to modified PHU(s) exhibiting Mw values greater than 5 000 Da, better greater than 7 500 Da, and especially greater than 10 000 Da. In some aspects, the Mw values may be of from 5 000 to 20 000 Da. Advantageously, it is highly desirable that the Mw values are above the entanglement molecular weight.

The main advantage of the process is the manufacture of aldehyde modified PHU(s), ketone modified PHU(s) and/or boronic acid modified PHU(s) exhibiting a reduced water adsorption (expressed in %).

Typically, the water adsorption is measured at various humidity environment, such as in a closed space, for example, a constant climate chamber or an experimental room, wherein the temperature and the humidity are maintained constant and defined as being for example a room humidity (45%) and/or 65%-85% humidity. The precise humidity measurement is realised either with electronic humidity controller or with a psychrometer in accordance with ASTM E337-15 standard.

Globally, the water adsorption (in wt.%) of the aldehyde modified PHU(s), ketone modified PHU(s) or boronic acid modified PHU(s), is found to be essentially constant from about 10 days. “Essentially” means, in the context of the invention, that the variations (deviations) of water adsorption are within the range of about 0,1 -0,2 wt.%. Typical values are, at room humidity (45%), less than 1 ,5 wt.%, preferably from 0,1 to 1 wt.%, better from 0,2 to 1 wt.%, said values being essentially constant after about 3 days of the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) exposition. When compared to starting non-modified PHll(s), the latter exhibit a value of at least 2 wt % of water adsorption, said value being constant and obtained after at least 8 days of exposition to the humidity.

Same tendency is observed when experiments are performed under 65% of humidity (same experimental conditions). Typical values are, at 65% of humidity, from 0,8 to 2,3 wt.%, better from 1 ,0 to 2,0 wt.%, said values being essentially constant after about 7 days of the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) exposition to humidity. When compared to starting non modified PHll(s), the latter exhibit a value of at least 3,5 wt.% of water adsorption, said value being essentially constant and obtained after at least 9 days of exposition to the humidity.

Experiments performed under 85% of humidity (same experimental conditions) show values of preferably from 2,1 to 4,3 wt.%, better from 2,3 to 4,0 wt.%, said values being essentially constant after about 9 days of the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) exposition. When compared to starting non modified PHll(s), the latter exhibit a value of at least 7,5 wt % of water adsorption, said value being essentially constant and obtained after at least 6 days of exposition to the humidity.

In some alternate embodiments, the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) are exhibiting a water adsorption (in wt %) which is reduced of at least 70% as compared to the starting non modified PHll(s), preferably the water adsorption being reduced from 1 ,7 to 10 fold with comparison to the starting non modified PHll(s), at same experimental conditions. For example, at room humidity, up to 5-fold water adsorption reduction may be observed; at 65% and 85% of humidity, up to 4-fold water adsorption reduction may be observed.

The process allows to obtain the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s), from a starting non modified PHU, which are exhibiting degrees of modification of at least 10%, preferably 10%-95% more preferably from 60% to 95%, better of from 80% to 95%. In some other embodiments, the degrees of modification may be of at least 75%, preferably of from 75% to 95%, better of from 80% to 92%. Said degrees of modification are determined using ¹H or ¹⁹F NMR method as determined by test method A or B, described in the experimental part. However, the one skilled in the art knows how to perform the NMR experiments in the field of the invention.

Another improved properties of the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) obtained through the process is (i) the maintenance of mechanical properties and (ii) reduced dependence of the mechanical properties on humidity in comparison with the starting non modified PHll(s), at same experimental conditions.

The dependence of the mechanical properties on humidity of the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) in comparison with the starting non modified PHll(s), at same experimental conditions, may be within the range of 50-120 fold lower.

For example, a graph related to the variation of the storage modulus (Pa) vs frequency (Hz) for starting non modified PHll(s), measured in accordance with the ASTM D5279- 21 standard, at room humidity (45%), 65% and 85% humidity respectively, shows high range values of the storage modulus within the frequency range of 0,5 Hz-20 Hz, typical respective values may be within the range 1700.10⁷ to 5,4.10⁷ Pa (variations of about 315 fold). For the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) obtained through the process, typical respective values may be within the range of 43.10⁷ to 7,4.10⁷ Pa (variations of about 6 fold), or 53.10⁷ to 20.10⁷ Pa (variations of about 2.60). These values of the storage modulus (Pa) vs frequency (Hz) show that that the mechanical properties are maintained within the same order of magnitude.

The obtained modified PHll(s) very advantageously exhibit a higher contact angle, measured in accordance with the ASTM D7334-08(2022) standard, for example, increased of about 5-36% in comparison with the starting non modified PHll(s), at same experimental conditions, demonstrating the increased hydrophobicity. In some embodiments, with the use of some specific aldehydes in the process, the aldehyde modified PH Us may exhibit some fluorescence or luminescence properties. This is especially the case when 4-butanal-8-hydroxycumarine is used.

Also, bio-based non modified PHU(s) are preferably used. Advantageously, the neat non-modified PHU compound of formula (I) may be a linear

PHU, or linear isomeric PHU, of formula (la) and/or a cycloaliphatic PHU of formula

wherein R” have the same meaning as above defined.

The process is carried out in the presence of a Bronsted acid type catalyst for aldehyde (II) and/or ketone (III) modification agents, being preferably selected from p- toluenesulfonic acid (p-TCA), hydrochloric acid (HCI), sulfuric acid (H₂SO₄), acetic acid (CH3COOH), methanesulfionic acid (CF3SO3H), tetrafluoroboric acid (HBF₄) and hexafluorophosphoric acid (HPF₆), and mixtures thereof. Said catalysts are used to catalyze intramolecular cyclization of adjacent hydroxyl groups in specific PHUs.

The Bronsted acid type catalyst may be used with aldehyde (II) and/or ketone (III) modification agents at 4-56 mol% of loading calculated per a repeating polymer unit.

The process is carried without any catalyst for the boronic acid (IV) modification agent, or in the presence of a Bronsted base type catalyst, being preferably selected from ammonia (NH₃), N-substituted amines (N(R””)₃, wherein R”” may be selected from the group consisting of a linear or branched Ci-Ci₄ alkyl or alkoxy group; a linear or branched C₂-Ci₄ alkenyl or alkylenoxy group; a linear or branched C₂-Ci₄ alkynyl group; a cyclo(C₃-C₆ alkyl) group; (CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, -(CH₂)_m-CF₃ group, -CH₂-(CF₂)_m-CF₃ group, o-, m-, p- substituted or unsubstituted phenyl group, pyridine (C₆H₅N), 1 ,8-diazabicyclo(5.4.0)undec-7-ene (DBU), Triazabicyclodecene (TBD), 7-Methyl-1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 2,3,4,6,7,8-Hexahydropyrrolo[1 ,2-a]pyrimidine and mixtures thereof.

The process is performed with the use of a solvent. Preferred solvents may be n- methyl-2-pyrrolidone (NMP), N,N-Dimethylformamide (DMF), N,N-Dimethylacetamide (DMAc), Dimethyl sulfoxide (DMSO) or any other polar solvent capable to dissolve the starting non modified PHll(s).

The temperatures ranges of the process, 40°C to 100°C, preferably of from 50°C to 90°C, for aldehyde (II) and/or ketone (III) modification agents or 25°C to 100°C, preferably of from 50°C to 90°C, for boronic acid (IV) modification agent respectively, are selected to avoid any degradation of the stating non-modified PHll(s), for example, the urethane linkage that may cause reversion to an unwanted isocyanate plus a hydroxyl compounds. The preferred temperature ranges in both cases are selected to optimally avoid the drawbacks previously cited.

The selected duration time of the reaction is of from 24h to 96h for aldehyde (II) and/or ketone (III) modification agents or 0.5h to 96h for boronic acid (IV) modification agent, and, without being bound by any theory, may be depending on the removal or not of the water formed, as side product, and/or whether the aldehyde or ketone is activated by presence of a certain functional groups or not.

The preferred duration may be within 24h to 85h, or even 48h-80h, which are the most preferable ranges for optimally avoid the drawbacks previously cited.

Preferably, R and R’, independently, are selected from the group consisting of a linear or branched C-i-C₈ alkyl or alkoxy group; a linear or branched C₂-C₈ alkenyl or alkylenoxy group; a linear or branched C₂-C₈ alkynyl group; a cyclo(C₃-C₆alkyl) group; said groups optionally containing one or more hetero atom; a heterocyclo(C₃-C₆ alkyl) group, wherein the hetero atom is selected from N, S, F and 0; at least one linear or branched C-i-C₆ alkyl group, C₂-C₆ alkenyl or alkylenoxy group, a linear or branched C₂-C₆ alkynyl group, -(CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, such as 0, N, S, -(CH₂)_m-CF₃ group o-, m-, p- substituted or unsubstituted phenyl group, polycyclic aromatic (PAH), heteroaromatic hydrocarbon and a keto heteroaromatic hydrocarbon, wherein m is of from 0 to 4, such as 4-butanal- 8-hydroxycumarine and HOC-(CH₂)_m-Ar preferably selected form a-tolyaldehyde, cinnamaldehyde and hydrocinnamaldehyde.

When the R group of compounds of formula (II) to (IV) is a phenyl group, polycyclic aromatic (PAH), heteroaromatic hydrocarbon and a keto heteroaromatic hydrocarbon, these may be substituted in ortho, meta and/or para position in the ring.

The neat non modified PHll(s) used as the starting material for the aldehyde modified PHll(s), ketone modified PHll(s) or boronic acid modified PHll(s) is/are synthesized through known step-growth polymerization of respective bis-cyclic carbonates and diamines (see Amaury Bossion cited above).

In some examples, the diamine reagent (defined for R”) may be hexamethylenediamine (HMDA) and the like, the dicarbonate reagent may be 1 ,2; 3,4- erythritol dicarbonate and 4-vinylcyclohexene dicarbonate.

Additionally, non-limitative examples of compound (II) are butyraldehyde, heptaldehyde, p-trifluoromethylbenzaldehyde, 3-phenylpropanal, of compound (III) are methylethyl ketone, and compound (IV) may be phenylboronic acid.

The invention also relates to modified poly(hydroxyurethanes) (PHUs) obtainable by the process of the invention presenting a linear structure of formula (V) and/or a cycloaliphatic structure of formula (VI) selected from the group consisting of

wherein R, R’, R” and n have the same meaning as above defined.

The modified poly(hydroxyurethanes) (PHUs) exhibit all the properties listed above.

In some embodiments, the modified linear poly(hydroxyurethanes) (PHUs) may exhibit modification degrees of at least 10%, preferably 10%-95%, more preferably from 60% to 95%, better of from 80% to 95%, in comparison to a starting non-modified PHU compound. In some other embodiments, the degrees of modification may be of at least 75%, preferably of from 75% to 95%, better of from 80% to 92%.

The invention will be described in some more details with accompanying figures. Figures 1a and 1 b represent respectively the ¹H NMR and ¹³C NMR of the modified PHU-compound A- of Example 1 obtained according to an embodiment of the invention. Figures 2a and 2b represent respectively the ¹H NMR and ¹³C NMR of the modified PHU-compound B- of Example 2 obtained according to an embodiment of the invention.

Figures 3a, 3b and 3c represent respectively the ¹H NMR,¹³C NMR and ¹⁹F NMR of the modified PHU-compound C- of Example 3 obtained according to an embodiment of the invention.

Figures 4a and 4b represent respectively the ¹H NMR and ¹³C NMR of the modified PHU-compound D- of Example 4 obtained according to an embodiment of the invention.

Figures 5a and 5b represent respectively the ¹H NMR and ¹³C NMR of the modified PHU-compound E- of Example 5 obtained according to an embodiment of the invention.

Figures 6a and 6b represent respectively the ¹H NMR and ¹³C NMR of the modified PHU-compound F- of Example 6 obtained according to an embodiment of the invention.

Figures 7a and 7b represent the ¹H NMR and ¹³C NMR of the modified PHU- compound G- of Example 7 obtained according to an embodiment of the invention.

Figure 8 represents the ¹H NMR of the modified PHU-compound H- of Example 8 obtained according to an embodiment of the invention.

Figures 9a, 9b and 9c represent respectively the ¹H NMR,¹³C NMR and ¹⁹F NMR of the modified PHU-compound I- of Example 9 obtained according to an embodiment of the invention.

Figure 10 represents the ¹H NMR of the modified PHU-compound J- of Example 10 obtained according to an embodiment of the invention.

Figure 11 represents Storage Modulus (G’, measured using rheology) plots of PU control, PHU1 control, Compound D and Compound C measured at different humidity levels (45, 65 and 85%). Figure 12 represents Storage Modulus (E’, measured using DMTA) and loss factor (tan 5) plots of Pll control, PHII1 control, Compound A, Compound B, Compound D and Compound C.

Mechanical properties of PHU samples, i.e. , o_t - tensile strength (kPa), E_t - tensile modulus (MPa) and £ - elongation (%) are measured at room temperature using a universal test machine Instron 5967 (Norwood, MA, USA) equipped with a load cell of 1 kN according to ASTM D882-18 and D638-14. The measurements were achieved at a crosshead speed of 5 mm/min. Before tests, samples were bar-shaped (40 x 10 x 2 mm) by using vacuum compression moulding MeltPrep (MeltPrep GmbH, Austria) machine at 90°C for modified PHU samples and at 120°C for non-modified ones under 1 mbar vacuum according to ASTM D4703 standard and stored during 72 h in the specified humidity conditions (45, 65 and 85%). At least 5 specimens were tested per reference.

The surface wettability (water contact angle, CA) of the aldehyde modified and control PHU(s) was measured in accordance with the ASTM D7334-08(2022) standard. CA measurements were performed on thin polymer films using the sessile drop method on a Contact Angle System OCA (Apollo Instruments) at 25°C and atmospheric pressure. A 10 pL drop of ultrapure deionized water was released through a motor- driven syringe onto the surface of the tested PHU film. The photo image of the drop was acquired after 15 seconds after the drop placement by a numerical camera and transmitted to a computer workstation to calculate the contact angle. The contact angles were calculated using SCA 20 v.2 software using automatic profile analysis protocol. Each reported value is an average of at least five independent measurements. Polymer films were casted on clean microscope glass slides from 0.1g/mL (PHU^ or 0.15g/mL (modified PHU! polymers) solutions in DMF filtered preliminarily through 0.2 pm syringe filter and allowed to slowly evaporate at 80°C on a heating plate. The obtained thin films were dried at 80°C/0.1 mbar for 12 h. After cooling down in vacuum to RT films were directly applied for CA analysis to prevent the adsorption of atmospheric moisture.

Water adsorption was measured for each polymer sample using bars (typical length x width x thickness = 20 x 5 x 1 .5 mm) at three humidity conditions: 45 (room humidity), 65 and 85% controlled according to ASTM E337-15. These bars were weighed after specified periods of time (24h, 72h, 7 days, 11 days) and water adsorption was calculated using the following formula:

The W.a. (%) = Weight of bar (stored at specified humidity for xh)/ Weight of bar (right after preparation) x 100%

NMR spectra were recorded on AMX-600 spectrometer (Broker, Germany) at 25°C in the indicated deuterated solvent and are listed in ppm. The signals corresponding to the residual protons and carbons of the deuterated solvent were used as an internal standard for ¹H and ¹³C NMR, respectively. The C₆F₆ was utilized as an external standard for ¹⁹F NMR.

Test method A for determination of PHll(s) modification degree. Modification degree was calculated from ¹H NMR spectrum especially according to the equation:

Mod. degree = ? — 100% (eq. 1 ) where I is the intensity of any signal originating from the moiety in the side polymer chain obtained after intramolecular cyclization with modification agent (for example, a signal at 0.91-0.82 ppm representing CH₃ group from butyl side chain in Compound A, Example 1 ) and normalized using the signal at 3.02-2.86 ppm (-CH₂-NH- group in polymer backbone), n_H is the theoretical number of H atoms in the above said moiety;

Test method B for determination of PHll(s) modification degree. This method can be used for PHUs modified with fluorine containing aldehydes, ketones or boronic acids. Modification degree was calculated from ¹⁹F NMR spectrum using the ratio between signals of any fluorine group or moiety in side polymer chain obtained after intramolecular cyclization with fluorinated modification agent (for example, a signal at -63.52 ppm representing -CF₃ group from p-CF₃ benzene ring in Compound C, Example 3) and normalized using the signal at -164.9 ppm of hexafluorobenzene (C₆F₆), added as an external standard, according to the equations 2 - 5:

(eq. 2) where ??_mod is the number of moles of modified repeating units in polymer chain, ?? is the number of moles of unmodified repeating units in polymer chain;

6,F 6,

(eq- 3) where I is the intensity of any fluorine moiety in side polymer chain obtained after intramolecular cyclization with fluorinated modification agent (for example, a signal at -63.52 ppm representing -CF₃ group from p-CF₃ benzene ring in Compound C, Example 3) and normalized using the signal at -164.9 ppm of hexafluorobenzene (C₆F₆), added as an external standardin ¹⁹F NMR spectrum; n_F is the theoretical number of F atoms in the above said moiety and ??„ _F is the number of moles of

^C6^/'6 hexafluorobenzene added to the NMR sample as an external standard;

77

■ ‘ unmod

(eq. 4) where is the weight of the polymer sample,

is the molecular weight of modified repeating unit, M_unmod is the molecular weight of unmodified repeating unit;

(eq- 5)

Thermoqravimetric analysis (TGA) of polymer samples was performed in accordance with ASTM E2550-17 standard. TGA was carried out in air on a TGA2 STARe System (Mettler Toledo) applying a heating rate of 5°C/min. The onset weight loss temperature (Tonset) was determined in accordance with the aforementioned standard, and then rounded to the nearest 5°C.

Differential Scanning Calorimetry (DSC) was performed in accordance with ASTM D3418-21 standard. Samples were hermetically sealed in Al pans in air and DSC analysis was performed on a DSC 300 Caliris Select differential calorimeter (NETZSCH) in the range of -50°C to 190°C. Two heating-cooling cycles with a heating rate of 10°C/min were carried out for each sample under N₂ atmosphere. The glass transition temperature (T_g) and melting temperature (T_m) were determined from the heating curve during the second heating cycle.

Dynamic Mechanical Thermal Analysis (DMTA) was carried out in accordance with the ASTM D4065-20 standard on polymer bars (typical length x width x thickness = 20 x 5 x 1 .5 mm) with a DMA 850 “Discovery” model (TA Instruments, USA) operating in tension mode (dynamic strain: 0.05 %, pretension (preload force): 0.01 N, force track: 110%). Experiments were performed at 1 Hz frequency with a heating rate of 5°C/min from 10 to 100°C. The set up provided the storage and loss moduli (E’ and E”). The damping parameter or loss factor (tan 5) was defined as the ratio tan 5 = E”/E’.

Rheology measurements were performed in torsion mode with bar geometry using an Anton Paar Physica MCR 302 rheometer equipped with a CTD 180 temperature control device and a humidity controller MHG100. Polymer samples in a form of bars (typical length x width x thickness = 20 x 5 x 1 .5 mm) were stored during 72 h in the specified humidity conditions (45, 65 and 85%) before measurement and then loaded directly in the clamping system. The samples were tested in accordance with ASTM D5279-21 standard in frequency sweep mode from 0.1 to 100 Hz and at an imposed 0.1 % shear strain, ensuring that both moduli G' and G" were obtained in the linear viscoelastic regime. All measurements were carried out at 25°C and constant humidity (45, 65 or 85%) maintained by MHG100 humidity controller. Tests were repeated at least twice to insure good repeatability of the results.

Examples In the examples, the following compounds are defined, as neat (starting) PHUs or non- modified PHUs

The following simplified formulas are used below for convenience:

In the examples, the following compound is defined, as Pll.

PU control

It was used as a reference for comparison of properties of modified and non-modified PHUs with regular PU presenting the most similar structure.

Example 1

The following synthesis of a modified PHU was performed (Compound A).

The PHU1 polymer (10.0 g, 34.48 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 80 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.489 g, 13.1 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, butyraldehyde (14.0 g, 194.14 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 9.4 g (79.2 %). Modification degree: 84%, calculated from ¹H NMR using ratio of signals -CH₃ (0.91 - 0.81 ppm)/-CH₂- (2.94 ppm). ¹H NMR (600 MHz, DMSO-d₆, 5): 7.28 - 6.65 (m, 2H), 5.26 - 3.37 (m, 7H), 2.94 (s, 4H), 1 .62 - 1 .25 (m, 8H), 1.22 (s, 4H), 0.91 - 0.81 (m, 3H). ¹³C NMR (151 MHz, DMSO, 5): 156.50, 155.90, 155.77, 154.90, 104.01 , 103.22, 100.79, 100.64, 79.71 , 76.78, 74.93, 74.81 , 70.25, 69.94, 67.34, 65.79, 63.37, 62.71 , 61.91 , 60.91 , 40.76, 40.21 , 40.06, 36.15, 35.98, 35.80, 35.61 , 35.23, 30.02, 29.41 , 29.32, 29.17, 25.99, 25.95, 25.91 , 24.69, 24.43, 17.07, 17.02, 16.96, 16.92, 16.84, 16.73, 14.32, 13.95, 13.88, 13.81 , 13.77. T_g (DSC, 10°C/min) = 44 °C. T_m (DSC, 10°C/min) = 108 °C. T_Onset (TGA, 5°C/min) = 185 °C. Anal. calcd. for Ci5.32H26.98N₂O6 (335.212): C, 54.89%; H, 8.11 %; N, 8.36%. Found: C, 55.02%; H, 8.0%; N, 8.2%.

Example 2

The following synthesis of a modified PHU was performed (Compound B).

The PHLI1 polymer (9.5 g, 32.76 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 80 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.365 g, 12.44 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, heptaldehyde (21.06 g, 184.43 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (2.9 ml) was added to mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 6.63 g (52.4 %). Modification degree: 84%, calculated from ¹H NMR using ratio of signals -CH₃ (0.92 - 0.81 ppm)/-CH₂- (2.94) ppm. ¹H NMR (600 MHz, DMSO-d₆, 5): 7.26 - 6.67 (m, 2H, -NH-), 5.24 - 3.40 (m, 7H), 2.94 (s, 4H), 1 .65 - 1.41 (m, 2H), 1.37 (s, 4H), 1.22 (m, 10H), 0.92 - 0.81 (m, 3H); ¹³C NMR (151 MHz, DMSO-d₆, 5): 158.07, 156.49, 155.75, 154.84, 103.38, 100.98, 95.17, 76.74, 74.92, 69.93, 65.78, 62.68, 61.90, 40.21 , 40.06, 33.54, 31.19, 31.17, 29.33, 28.60, 28.49, 25.97, 23.56, 23.31 , 22.00, 21.94, 13.89. T_g (DSC, 10°C/min) = 36°C. T_m (DSC, 10°C/min) = 111 °C. T_Onset (TGA, 5°C/min) = 215°C. Anal, calcd. for C17.74H3-1 ₈4N₂O₆ (369.178): C, 57.72%; H, 8.69%; N, 7.59%. Found: C, 56.29%; H, 8.14%; N, 7.36%.

Example 3

The following synthesis of a modified PHU was performed (Compound C).

The PHLI1 polymer (10 g, 34.48 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 80 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.489 g, 13.1 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, p-trifluoromethylbenzaldehyde (33.8 g, 194.14 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 9.3 g (60.5 %). Modification degree: 61 %, calculated independently from ¹H NMR (using the ratio of signals at 7.97-7.55 ppm and 3.02-2.86 ppm) and from ¹⁹F NMR with external standard - hexafluorobenzene (17.5 mg of C₆F₆ and 38.0 mg of polymer, using the ratio of signals at -63.52 ppm and -164.9 ppm). ¹H NMR (600 MHz, DMSO-d₆, 5): 7.96 - 7.56 (m, 2H), 7.45 - 6.67 (m, 2H), 6.25 - 5.15 (m, 1 H), 5.06 - 3.48 (m, 7H), 2.95 (s, 4H), 1.36 (s, 4H), 1.23 (s, 4H). ¹³C NMR (151 MHz, DMSO-d₆, 5): 156.52, 155.89, 155.76, 154.88, 141.64, 141.36, 130.06, 129.85, 129.59, 129.38, 128.37, 127.86, 127.61 , 127.31 , 127.08, 126.95, 125.18, 124.98, 123.18, 102.18, 101.58, 98.99, 98.89, 80.27, 77.32, 76.77, 76.33, 75.77, 70.68, 69.96, 67.79, 67.73, 65.80, 65.06, 63.21 , 62.55, 61.87, 60.79, 60.50, 59.83, 29.41 , 29.33, 29.21 , 26.02, 25.99. ¹⁹F NMR (565 MHz, DMSO- d₆) 5 -63.52. T_g (DSC, 10°C/min) = 59°C. T_onset (TGA, 5°C/min) = 195°C. Anal, calcd. for Ci6.88H23.83N2OeF1.83 (385.541 ): C, 52.59%; H, 6.23%; N, 6.66%. Found: C, 52.56%; H, 6.0%; N, 7.27%.

Example 4

The following synthesis of a modified PHU was performed (Compound D).

The PHU1 polymer (10 g, 34.48 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 80 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.489 g, 13.1 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, 3-phenylpropanal (26.05 g, 194.14 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 5.42 g (38.7 %). Modification degree: 80%, calculated from ¹H NMR using the ratio of signals of -CH2- at 1.92 - 1.68 ppm and of -CH2- at 2.93 ppm. ¹H NMR (600 MHz, DMSO-d₆, 5): 7.44 - 6.64 (m, 7H), 5.28 - 3.35 (m, 7H), 2.93 (s, 4H), 2.63 (q, J = 8.9 Hz, 2H), 1.92 - 1 .68 (m, 2H), 1 .35 (s, 4H), 1 .20 (s, 4H). ¹³C NMR (151 MHz, DMSO-d₆, 5): 156.48, 155.76, 154.86, 141.31 , 141.21 , 128.29, 128.21 , 128.18, 128.14, 125.78, 102.68, 100.27, 76.90, 75.07, 69.93, 67.37, 65.78, 62.65, 61.88, 40.43, 40.22, 40.06, 35.36, 35.13, 30.67, 29.62, 29.31 , 29.26, 25.96, 25.93. T_g (DSC, 10°C/min) = 46°C. T_Onset (TGA, 5°C/min) = 225°C. Anal, calcd. for C19.2H28.4N2O6 (383.246): C, 60.17%; H, 7.47%; N, 7.31 %. Found: C, 61.26%; H, 7.25%; N, 6.97%.

Example 5

The following synthesis of a modified PHU was performed (Compound E).

The PHU1 polymer (10 g, 34.48 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 80 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.489 g, 13.1 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, benzaldehyde (20.6 g, 194.14 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 7.65 g (58.7 %). Modification degree: 43%, calculated from ¹ H NMR using the ratio of signals corresponding to protons in -CebU group at 7.46 - 7.28 ppm and to -CH₂- at 2.95 ppm. ¹H NMR (600 MHz, DMSO-d₆, 6): 7.46 - 7.28 (m, 2H), 7.28 - 6.67 (m, 2H), 6.13 - 3.47 (m, 8H), 2.95 (dd, J = 14.4, 6.9 Hz, 4H), 1.44 - 1.31 (s, 4H), 1.23 (s, 4H). ¹³C NMR (151 MHz, DMSO-d₆, 5): 156.50, 155.89, 155.78, 154.91 , 137.52, 136.85, 136.19, 130.45, 129.50, 128.93, 128.61 , 128.26, 128.19, 128.05, 127.96, 127.77, 127.04, 126.85, 126.53, 126.33, 126.23, 102.67, 100.12, 100.01 , 80.17, 77.22, 76.75, 75.48, 75.32, 70.66, 69.94, 67.93, 67.71 , 67.02, 65.79, 65.45, 65.06, 64.91 , 64.15, 62.64, 61.95, 61.54, 60.89, 60.48, 59.82, 45.75, 40.78, 40.20, 40.06, 30.45, 29.42, 29.33, 29.19, 26.52, 26.00, 25.12, 15.16. T_g (DSC, 10°C/min) = 50°C. T_m (DSC, 10°C/min) = 100°C. T_Onset (TGA, 5°C/min) = 205°C.

Example 6

The following synthesis of a modified PHU was performed (Compound F).

The PHU1 polymer (10 g, 34.48 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 70 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (2.489 g, 13.1 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, 4-formylbenzonitrile (25.46 g, 194.14 mmol) dissolved in 10 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 4.98 g (42.0 %). Modification degree: 51 %, calculated from ¹H NMR using ratio of signals corresponding to protons in -C₆H₄-CN at 7.98 - 7.49 ppm and to -CH₂- at 2.94 ppm. ¹H NMR (600 MHz, DMSO-d₆, 5): 7.98 - 7.49 (m, 2H), 7.45 - 6.67 (m, 2H), 6.07 - 3.45 (m, 8H), 2.94 (s, 4H), 1 .37 (s, 4H), 1 .22 (s, 4H). ¹³C NMR (151 MHz, DMSO-d₆, 5): 156.50, 155.72, 151.00, 141.93, 132.66, 132.35, 132.29, 132.20, 132.16, 132.10, 128.38, 127.95, 127.74, 127.43, 127.19, 127.03, 126.73, 118.92, 118.54, 112.26, 109.61 , 102.17, 101.42, 75.79, 69.93, 68.23, 67.92, 67.14, 65.78, 61.82, 59.82, 52.31 , 40.19, 40.05, 30.33, 30.01 , 29.41 , 29.32, 25.99. T_g (DSC, 10°C/min) = 55°C. T_m (DSC, 10°C/min) = 119°C. T_Onset (TGA, 5°C/min) = 175°C.

Example 7

The following synthesis of a modified PHU was performed (Compound G).

The PHU2 polymer (7.9 g, 22.94 mmol) derived from 4-vinylcyclohexene dicarbonate (VCHBC) and hexamethylenediamine (HMDA) was placed in a 250 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 60 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p- TSA) (1.656 g, 8.71 mmol) in 5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, 3-phenylpropanal (17.33 g, 129.14 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70 °C for 72 h. After the completion of the reaction triethylamine (3 ml) was added to reaction mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 7.45 g (72.1 %). Modification degree: 50%, calculated from ¹H NMR using the ratio of signals at 2.79 - 2.65 ppm and 2.94 ppm. ¹H NMR (600 MHz, DMSO-d₆, 5): 7.38 - 7.12 (m, 5H), 7.08 - 6.57 (m, 2H), 4.94 - 3.37 (m, 9H), 2.94 (s, 4H), 2.79 - 2.65 (m, 1 H), 2.07 - 1 .42 (m, 7H), 1 .36 (s, 4H), 1 .23 (s, 4H), 1.18 - 1.00 (m, 1 H). ¹³C NMR (151 MHz, DMSO-d₆, 6): 194.98, 156.38, 156.31 , 155.78, 145.83, 141.95, 140.74, 139.16, 138.59, 137.82, 137.54, 128.85, 128.81 , 128.71 , 128.58, 128.37, 128.35, 128.30, 128.27, 128.24, 128.22, 128.17, 126.95, 126.85, 126.08, 125.86, 108.53, 71.44, 69.32, 60.72, 54.91 , 48.87, 37.15, 36.90, 33.65, 30.63, 29.42, 28.82, 26.01. T_g (DSC, 10°C/min) = 70°C. T_On_Set (TGA, 5°C/min) = 145°C.

Example 8

The following synthesis of a modified PHU was performed (Compound H).

The PHU1 polymer (1.5 g, 5.172 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 25 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 18 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then, the solution of phenylboronic acid (3.55 g, 29.12 mmol) in 10 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe in one shot to the reaction mixture and the resulting solution was stirred at 70°C for 72 h. After completion of the reaction, it was cooled down to room temperature with stirring for 1 h. The polymer was precipitated into the excess of diethyl ether, isolated by filtration and dried in vacuum at 80°C/1 mbar for 12h. Yield: 1.59 g (89.4 %). Modification degree: 95%, calculated from ¹H NMR using the ratio of signals at 7.68 ppm (-B-CebU of Ph-B moiety) and 2.95 ppm (-CH₂-). ¹H NMR (600 MHz, DMSO-d₆, 6): 7.68 (d, J = 7.3 Hz, 2H), 7.53 - 7.42 (m, 1 H), 7.36 - 7.30 (m, 2H), 7.30 - 6.74 (m, 2H), 5.79 - 3.47 (m, 7H), 2.92 (s, 4H), 1.33 (s, 4H), 1.18 (s, 4H).

Example 9

The following synthesis of a modified PHU was performed (Compound I).

The PHLI1 polymer (2.69 g, 9.27 mmol) derived from 1 ,2:3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 100 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 31 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (0.67 g, 3.52 mmol) in 4.5 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, 3,3,4,4,5,5,6,6,7,7,7-undecafluoroheptanal (16.28 g, 52.17 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (0.9 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 2.85 g (52.7 %). Modification degree: 35%, calculated using ¹⁹F NMR spectrum with hexafluorobenzene as external standard (23 mg of polymer and 12.1 mg of hexafluorobenzene) using the ratio of signals at -82.69 ppm (-CF₃) and -164.9 ppm (C₆F₆). ¹H NMR (600 MHz, DMSO-d₆, 5): 7.23 - 6.63 (m, 2H), 5.52 - 3.40 (m, 10H), 2.94 (s, 4H), 1.37 (s, 4H), 1.23 (s, 5H). ¹³C NMR (151 MHz, DMSO, 5): 156.51 , 155.85, 154.87, 76.76, 69.94, 69.03, 67.93, 67.71 , 65.79, 65.46, 65.06, 64.14, 59.81 , 45.78, 40.75, 40.20, 40.05, 29.42, 26.01 , 25.74, 8.62. ¹⁹F NMR (565 MHz, DMSO-d₆, 5): -82.69, -108.53, -117.20, -123.57, - 124.27, -124.56, -124.92, -128.24. T_g (DSC, 10°C/min) = 42°C. T_m (DSC, 10°C/min) = 111 °C. Tonset (TGA, 5°C/min) = 155°C. Example 10

The following synthesis of a modified PHU was performed (Compound J).

The PHU1 polymer (2.0 g, 6.9 mmol) derived from 1 ,2: 3,4-erythritol dicarbonate (EDC) and hexamethylenediamine (HMDA) was placed in a 100 ml round bottom flask equipped with magnetic stirrer. Then the flask was closed with septum, evacuated, and filled with argon. The 20 ml of anhydrous N-methyl-2-pyrrolidone was added to the flask using syringe and the polymer was dissolved over 1 hour at 70°C with continuous stirring. Then the solution of a catalyst - p-toluenesulfonic acid (p-TSA) (0.498 g, 2.62 mmol) in 4 ml of anhydrous N-methyl-2-pyrrolidone was added via syringe and stirred over 5 minutes. Finally, methylethyl ketone (2.8 g, 38.83 mmol) was added via syringe in one shot and the reaction mixture was stirred at 70°C for 72 h. After the completion of the reaction triethylamine (0.8 ml) was added to the mixture to quench the catalyst and the flask was cooled down to room temperature with stirring for 1 hour. The obtained polymer solution was precipitated into the excess of water. Solvents were removed by decantation and the obtained polymer was dried at 60°C/1 mbar for 1 h. Afterwards it was redissolved in tetrahydrofuran and precipitated into the excess of diethyl ether. The precipitated polymer was isolated by filtration and dried at 80°C/1 mbar for 12 h. Yield: 1.27 g (53.5 %). Modification degree: 11 %, calculated from ¹H NMR spectrum using the ratio of signals at 0.89-0.79 ppm (-CH₃) and 2.95 ppm (-CH₂-). ¹H NMR (600 MHz, DMSO-d₆, 5): 7.29 - 6.56 (m, 2H), 5.26 - 3.41 (m, 8H), 2.94 (q, J = 6.8 Hz, 4H), 1.37 (t, J = 7.1 Hz, 4H), 1.23 (p, J = 4.2 Hz, 4H), 0.84 (dtd, J = 11.2, 7.5, 4.3 Hz, OH). T_g (DSC, 10°C/min) = 47°C. T_On_Set (TGA, 5°C/min) = 185°C. The following Tables 1 & 2 are depicting the characteristics of the compounds from Examples 1 -7.

Table 1. Properties of modified PHII1 and control PHLI1 and Pll samples.

^a By DSC in N₂ at heating rate of 10°C/min, T_m was taken as peak maximum; ^b By TGA in air at a heating rate of 5°C/min; ^c Storage modulus (E’) and T_a (taken as peak maximum from the tan 5 curve) measured by DMTA at a heating rate of 5 °C/min; ^d Determined after 11 days of conditioning at selected humidity levels and 22 °C; ^e Storage modulus (G’) at 0.1 Hz measured via torsional rheometry at 25 °C and indicated humidity level after conditioning at selected humidity levels and 22 °C for 3 days; 9 Water contact angle measured on films at 22 °C. Table 2. Properties of modified PHLI2 sample and control PHLI2 sample.

^a By DSC in N₂ at heating rate of 10°C/min; ^b by TGA in air at a heating rate of

5°C/min; ^c Determined after 11 days of conditioning at selected humidity levels and

22 °C; ^d Storage modulus (G’) at 0.1 Hz measured via torsional rheometry at 25 °C and indicated humidity level after conditioning at selected humidity levels and 22 °C for 3 days; ^e Water contact angle measured on films at 22 °C.

Claims

Claims

1. A process for preparing a modified linear polyhydroxyurethane (PHU) via intramolecular cyclization reactions comprising the step of: reacting a starting non-modified PHU compound, having repeating units, containing two proximate hydroxyl groups separated by 2 to 7 atoms, of formula (I)

wherein

- n, is integer of from 5 to 150;

- R” is derived from a diamine reagent and is comprised of one or more of the following entities selected from the group consisting of: linear or branched aliphatic, cycloaliphatic and aromatic moieties, oligomeric/(co-)polymeric species, such as poly(alkylene oxides), poly(siloxanes), poly(dienes), poly(olefins), poly(amides), and (co-)polymeric species in the form of am ineterminated oligomers;

- R’” is derived from a dicarbonate reagent which consists of terminal carbonate groups, and is comprised of one or more of the following entities selected from the group consisting: linear or branched aliphatic, cycloaliphatic, and aromatic moieties; and additionally, that contains at least 2 hydroxyl functionalities (-OH), said hydroxyl functionalities being separated by no more than 7 atoms; and presenting a molecular weight of no more than 400 g/mol; with a chemical capable of ring formation with the hydroxyl functionalities, selected from the group consisting of an aldehyde compound of formula (II), ketone compound of formula (III) and boronic acid compound of formula (IV)

in the presence of a Bronsted acid type catalyst, and a solvent, and using a stoichiometric ratio of compound (II) and/or (III) to the repeating unit of polymer (I) of between 0.1 :1 and 100:1 by mol, at a temperature range of from 40°C to 100°C, during 24h-96h, or without any catalyst or in the presence of a Bronsted base type catalyst, and a solvent, and using a stoichiometric ratio of compound (IV) to the repeating unit of polymer (I) of between 0.1 :1 and 100:1 by mol, at a temperature range of from 25°C to 100°C, during 0.5h-96h, wherein

- R, R’ are, independently, selected from the group consisting of a linear or branched C-|-C₁₀ alkyl or alkoxy group; a linear or branched C₂-C₁₀ alkenyl or alkylenoxy group; a linear or branched C₂-C-i₀ alkynyl group; a cyclo(C₃-C6 alkyl) group; said groups optionally containing one or more hetero atoms; a heterocyclo(C₃-C6 alkyl) group, wherein the hetero atom is selected from N, S, F and O; at least one linear or branched C-|-C₆ alkyl group, C₂-C₆ alkenyl or alkylenoxy group, a linear or branched C₂-C₆ alkynyl group, (CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, -(CH₂)_m-CF₃ group, -CH₂-(CF₂)_m-CF₃ group, o-, m-, p- substituted or unsubstituted phenyl group, polycyclic aromatic (PAH), heteroaromatic hydrocarbon and a keto heteroaromatic hydrocarbon, wherein m is of from 0 to 6.

2. The process according to claim 1 , wherein the starting non-modified PHU compound of formula (I) is an isomeric linear PHU of formula (la) and/or a cycloaliphatic PHU of formula (lb)

3. The process according to claim 1 or 2, wherein

R and R’, independently, are selected from the group consisting of a linear or branched C-|-C₈ alkyl or alkoxy group; a linear or branched C₂-C₈ alkenyl or alkylenoxy group; a linear or branched C₂-C₈ alkynyl group; a cyclo(C3-C₆alkyl) group; said groups optionally containing one or more hetero atoms; a heterocyclo(C₃-C6 alkyl) group, wherein the hetero atom is selected from N, S, F and 0; at least one linear or branched C-|-C₆ alkyl group, C₂-C₆ alkenyl or alkylenoxy group, a linear or branched C₂-C₆ alkynyl group; -(CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, such as 0, N, S; -(CH₂)_m-CF₃ group o-, m-, p- substituted or unsubstituted phenyl group, polycyclic aromatic (PAH), heteroaromatic hydrocarbon and a keto heteroaromatic hydrocarbon, wherein m is of from 0 to 4, such as 4-butanal-8-hydroxycumarine and HOC-(CH₂)_m-Ar preferably selected form a-tolyaldehyde, cinnamaldehyde and hydrocinnamaldehyde.

4. The process according to any of claims 1-3, wherein the Bronsted acid type catalyst for aldehyde (II) or ketone (III) modification agents is selected from p- toluenesulfonic acid (p-TCA), hydrochloric acid (HCI), sulfuric acid (H₂SO₄), acetic acid (CH₃COOH), methanesulfionic acid (CF3SO3H), tetrafluoroboric acid (HBF₄) and hexafluorophosphoric acid (HPF₆), and mixtures thereof.

5. The process according to any of claims 1 -4, wherein it is conducted without any catalyst for boronic acid (IV) modification agent, or in the presence of a Bronsted base type catalyst, being preferably selected from ammonia (NH₃), N- substituted amines (N(R””)₃, wherein R”” can be selected from the group consisting of a linear or branched C-i-C-i₄ alkyl or alkoxy group; a linear or branched C₂-C₁₄ alkenyl or alkylenoxy group; a linear or branched C₂-C₁₄ alkynyl group; a cyclo(C₃-C6 alkyl) group; (CH₂)_m-Ar group, where Ar is any aromatic ring or condensed aromatic ring, additionally substituted or unsubstituted, optionally including heterocycles, -(CH₂)_m-CF₃ group, -CH₂- (CF₂)_m-CF₃ group, o-, m-, p- substituted or unsubstituted phenyl group, pyridine (C₆H₅N), 1 ,8-diazabicyclo(5.4.0)undec-7-ene (DBU), triazabicyclodecene (TBD), 7-Methyl-1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 2, 3, 4, 6,7,8- Hexahydropyrrolo[1 ,2-a]pyrimidine and mixtures thereof.

6. The process according to any of claims 1 -5, wherein the solvent is selected from n-methyl-2-pyrrolidone (NMP), N,N-Dimethylformamide (DMF), N,N- Dimethylacetamide (DMAC), Dimethyl sulfoxide (DMSO), and mixture thereof, or other polar solvent capable to dissolve the starting non modified PHll(s).

7. Modified poly(hydroxyurethanes) (PHUs) obtainable by the process of any of claims 1 -6 presenting an isomeric linear structure of formula (V) and/or a cycloaliphatic structure of formula (VI) selected from the group consisting of

wherein R, R’, R” and n have the same meaning as defined in any of claims 1-5.

8. The linear modified poly(hydroxyurethanes) according to claim 7, wherein said modified linear poly(hydroxyurethanes) is aldehyde modified PHUs, ketone modified PHUs and/or boronic acid modified PHUs.

9. The linear modified poly(hydroxyurethanes) according to claim 7 or 8, wherein said modified linear PHU(s) are exhibiting a water adsorption, in wt. %, which is reduced of at least 70% as compared to the starting non modified PHU(s), said water adsorption being measured according to with ASTM E337-15 standard, preferably the water adsorption being reduced from 1 ,7 to 10 fold with comparison to the starting non modified PHU(s), at same experimental conditions.

10. The modified linear poly(hydroxyurethanes) according to any of claims 7 to 9, wherein the modified PHll(s) exhibit an increased contact angle, measured in accordance with the ASTM D7334-08(2022) standard of about 5-36% in comparison with the starting non modified PHll(s), at same experimental conditions.

11 . The modified linear poly(hydroxyurethanes) according to any of claims 7 to 10, wherein the modified linear poly(hydroxyurethanes) (PHUs) exhibit of at least 10%, preferably 10%-95%, more preferably from 60% to 95%, better of from 80% to 95%, in comparison to a starting non-modified PHU compound, said modification degrees being determined using ¹H or ¹⁹F NMR.