WO2009077202A1 - Production and use of polysaccharide graft copolymers - Google Patents

Abstract

The present invention relates to a method for producing polysaccharide graft copolymers, starting with amino derivates of polysaccharides that are polymerized with a radically polymerizable monomer while adding an oxidant and a radical starter.

Description

 Production and Use of Polysaccharide Graft Copolymers

The present invention relates to a process for the preparation of polysaccharide graft copolymers, starting from amino derivatives of polysaccharides and polymerizing them with a free-radically polymerizable monomer with the addition of an oxidizing agent and a radical initiator.

The reaction for the preparation of diethylaminoethyl starch derivatives has been known since the 1950s and sufficiently described for various non-soluble starch derivatives as a slurry reaction (US Pat. No. 2,917,506, US Pat. No. 2,935,436, US Pat. No. 2,813,093 and GB 765 880).

The object of the present invention was to provide a process for the preparation of polysaccharide graft copolymers, with which high yields can be achieved. It was also an object of the present invention to provide by this method products which have better physical properties than previous derivatives.

This object is achieved with respect to the method with the features of claim 1, with respect to the graft copolymer having the features of claim 28 and with respect to a coating with the features of claim 29. Claim 30 discloses uses of the graft copolymers. The dependent claims represent advantageous developments of the method.

The invention thus provides a process for the preparation of polysaccharide graft copolymers, starting from at least one amino derivative of a polysaccharide and / or a mixture containing at least one polysaccharide. The amino derivative here has the general formula I:

Formula I The radicals contained in general formula I in this case each independently

A = oxygen, NR ⁴ or [N (R ⁴ ) ₂ ] ⁺ / X ^" , with R ⁴ independently of one another selected from the group consisting of hydrogen, linear or branched C ₁ -C ₂ -alkyl, C ₁ -C ₄ -alkyl ₂ -alkenyl, C ₁ -C ₂ -AIkXnVl, C ₇ - C ₈ aralkyl, C ₆ -C ₈ -aryl, C ₆ -C ₈ -Heteroarylsub- substituents and / or -C (O) - ( CH ₂ ) _X -CH ₃ with x = 0 to 11, where X ^"is a negatively charged counterion. In particular, however, A here is oxygen, NH, NC (O) -Me or a mixture of NC (O) -Me and NH;

R ¹ = independently selected from the group consisting of linear or branched Ci-Ci ₂ - alkyl, Ci-Ci ₂ alkenyl, Ci-Ci ₂ alkynyl, C ₇ -Ci ₈ - aralkyl, C ₆ -Ci ₈ -aryl, heteroaryl, hydroxy, Ci-Ci ₂ -alkoxy, amino substituents and / or two radicals R ^{1 of} two vicinal carbon atoms together form a ring which may be aliphatic or aromatic, may contain heteroatoms and 1 to Has 8 ring members. In particular, R ^{1 is} hydrogen.

R ² = independently selected from the group consisting of hydrogen, linear or branched _Ci-C12 alkyl, _Ci-Ci2 alkenyl, Ci-Ci ₂ - alkynyl, C ₇ -C ₈ -Aralkylsubstituenten and / or two R ² radicals together form a ring which is aliphatic, may contain heteroatoms and has 1 to 8 ring members. R ² is particularly preferably a short-chain alkyl radical, such as, for example, methyl, ethyl, propyl, butyl, in particular an ethyl radical (Et). independently selected from the group consisting of -CH ₂ OH, -CH ₂ OR ⁴ , -CH ₂ O- (CH ₂ ) _m -OH with m = 1 to 12, -COOH, -COO ^* Y ⁺ where Y ^{+ is} a positive charged counterion is -COOR ⁴ where R ⁴ is as defined above; or one

Represents -CH ₂ O- group which is α-1,6 glycosidically connected to another amino derivative of the general formula I. R ³ may be the same or different for the illustrated monomeric units of the formula I. Thus corresponds

R ³ , if the polysaccharide is unsubstituted at the carbon atom 5 of the underlying glucopyranose unit, a -CH ₂ OH grouping. Alternatively, however, it is also possible that at least some of these free CH ₂ OH groups are etherified, esterified, oxidized or α-1, 6-glycosidically bound. For example, the functionalities mentioned above may be appropriate here, with particular preference being given to carboxymethyl radicals (-CH ₂ -O-CH ₂ -COONa) and / or hydroxyethyl radicals (-CH ₂ O (CH ₂ ) ₂ OH). Two alternative preferred possibilities are conceivable here, namely that unsubstituted polysaccharide derivatives are used on the carbon atom 5, ie all of them

R ³ radicals of the grouping correspond to -CH ₂ OH-, or that these -CH ₂ OH groups are at least partially substituted. In this case, this is due to this partial substitution of the - CH ₂ OH group by the above-mentioned possible

Grouping preferred degree of substitution of the radical R ³ (DS (R ³ )) between 0.1 and 0.95, more preferably between 0.25 and 0.65. By this is meant that the indicated fraction of the free -CH ₂ OH groups by the alternative groups given for R ³ , ie other than CH ₂ OH, is replaced. The substitution of the -CH ₂ OH groups of the glycopyranose units is carried out statistically with respect to the three monomeric units shown in formula I.

The index n mentioned in formula I is from 0 to 10 according to the invention.

The group B of the middle monomer unit of the formula I is independently selected from the group consisting of - [N (R ⁴ ) ₃ ] ⁺ / X ^" , or groups of the formulas II, III or IV

II III IV

II III IV

where A, R ¹ , R ⁴ , m, X ^" and Y ^{+ have} the abovementioned meaning.

It is particularly preferred for the radicals when m = 1 and n = 0. A particularly preferred radical R ⁴ is methyl.

The ratios of the individual monomer units of the formula I according to the invention (corresponding to the respective degrees of substitution) to one another thereby move

• for a / (a + b + c) in a range from 0.01 to 0.95, • for b / (a + b + c) from 0 to 0.9 as well

• for c / (a + b + c) from 0.05 to 0.99.

According to the invention, it is also possible that the underlying monomeric saccharide units of the amino derivative of the formula I also different than on the mapped manner, α-1,4- or β-1,4 glycosidically linked together and may also be included as monomers in the mixture. According to the invention, this is understood to mean that any arrangement of the monomer units in the polymeric framework is possible, which may also be arranged, for example, in blocks, statistically or in any other way. The possibility that both α-1,4- and β-1,4-glycosidic linkages are possible is indicated in the general formula I by the wavy bond at the anomeric carbon atom. Likewise, it is possible according to the invention that the units on which the amino derivative of the formula I is based can be present as monomers in the mixture. These monomers can be represented by the following formulas:

Monomeric saccharide unit 1

Monomeric saccharide unit 2

Monomeric saccharide unit 3 The variables A, B, R ¹ , R ² , R ³ and n given in the formulas have the same definitions as stated above. Thus, there is the possibility that the aminoderivative-containing mixture has been subjected to partial hydrolysis. This means that in the preparation of the mixture comprising the amino derivative of general formula I, for example, maltodextrin, that is degraded glucose, can be used. Alternatively, for example, a hydrolytic degradation of the amino derivative of the formula I is possible to obtain the corresponding mixture. The stated monomers can be present in both .alpha.- and .beta.-anomeric form.

The counterions X ^" and Y ⁺ have no particularly relevant influence, neither on the process nor on the graft copolymers produced, Thus, the counterions X ^' and Y ^{+ can be selected} by the person skilled in the art on the basis of his

Expert knowledge are freely chosen. Preferred counterions X ^" are, for example: F ^" , Cl ^" , Br ^" , I ^" , triflate, tosylate, acetate, sulfate and / or monomethyl sulfate Preferred counterions Y ⁺ are, for example: Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ^+, Mg ^2+, Ca ^2+, Sr ^2+, Ba ^2+, Al ^3+, Fe ^2+,

Fe ³⁺ , Zn ²⁺ and / or combinations. The stoichiometry of the counterions is chosen according to their charge equivalents, so that the molecule of formula I or mixture containing the amino derivative of formula I, a total of charge-neutral molecule or mixture results.

In the process according to the invention, the amino derivative of the formula I or mixture as defined above is mixed with at least one free-radically polymerizable monomer to be grafted on and introduced Oxidizing agent added in combination with a radical initiator.

In contrast to the known from the prior art, the usual one-step process (initiation only with oxidizing agent), in which the degrees of conversion are very low, it has now surprisingly been found that in the inventive method, on the one hand higher degrees of conversion are obtained, for - Of which the polymers are characterized by better physical properties, such as film formation, transparency, stability, etc., compared to the previous polymers prepared by single-stage polymerization or by mixtures of starches with polyvinylpyrrolidone.

To clarify the method, an exemplary reaction equation is given below, in which the method steps are summarized in an overview. The radical R mentioned in the equation here corresponds to the radical R ^{2 of} the general formula I and is here preferably ethyl, - the radical M mentioned in the product formula represents the free-radically polymerized NVP chain.

Die radikalisch verlaufende Pfropfcopolymerisation des NVP bildet dabei mehr oder weniger lange oligome- re oder polymere PVP-Stränge, deren radikalische Zwischenstufen eine Ethylgruppe (Rest R) angreifen kön- nen und daran anbinden. Diese aufgepfropften PVP-

The free-radical graft copolymerization of the NVP forms more or less long oligomeric or polymeric PVP strands whose radical intermediates can attack an ethyl group (radical R) and attach to it. These grafted PVP

Chains may be present as graft chains, but there is also the possibility that the underlying polysaccharide chains will be cross-linked.

However, as a side reaction, homopolymerization of the synthetic monomer also occurs according to the following scheme.

Mechanism: Oxidation of the amine function to radical free radical polymerization

Here is the mechanism of radical formation through oxidation of tert. Amine derivatives shown. The radical R here represents the saccharide polymer backbone.

However, the method of the invention is not limited to this example. It is preferred if the at least one monomer contains a vinyl group. In particular, the monomer is selected from the group consisting of vinylpyrrolidones, in particular N-vinylpyrrolidone; Alkylene glycol di (meth) acrylates, especially ethylene glycol dimethacrylate; Alkylene, - (meth) acrylates; ω-hydroxyalkyl (meth) acrylates, especially 2-hydroxyethyl (meth) acrylate; acrylamide; styrenes; Vinyl lactams and / or mixtures thereof. A preferred mixture of the abovementioned monomers is, for example, a mixture of a vinylpyrrolidone and an alkylene glycol di (meth) acrylate, in particular ethylene glycol di (meth) acrylate. A further preferred mixture is, for example, 2-hydroxyethyl (meth) acrylate and ethylene glycol di (meth) acrylate. The bracketed (meth) means that the methyl group is optional and the corresponding acrylate is also preferred.

Advantageous oxidizing agents are, for example, hypochlorites, permanganates, peroxodisulfates, e.g. Sodium persulfate, peroxides, hyperoxides, superoxides and / or hydrogen peroxide. The substances mentioned can also be used as mixtures.

As a preferred free radical initiator an azo initiator is used in particular. Here are preferably in question:

• Hydrophilic azo initiators such as 2, 2 ^■ azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] disulphate dihydrate, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2'-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis (1) imino-1-pyrrolidino-2-ethylpropane) this hydrochloride, 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2 ' Azobis [2-methyl-N- (2-hydroxyethyl) propionamide];

Lipophilic azo initiators, such as 2, 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2-methylpropionitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2 ' -Azobis [N-

(2-propenyl) -2-methylpropionamide], 1- [(1-cyano-1-methylethyl) azo] formamide, 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis ( N-cyclohexyl-2-methylpropionamide);

Macroazoinitiators, e.g. diazo compounds based on polysiloxane, polyethylene glycol and / or on their block copolymers formed with vinyl monometers, preferably having a weight-average molecular weight of between 500 and 20,000 g / mol,

• and / or mixtures thereof.

The process is preferably carried out in water, furthermore in particular at least one base is added. The base is preferably selected from the group consisting of sodium hydroxide solution, potassium hydroxide solution, and / or mixtures thereof. By addition of the base is achieved that a specific pH of the reaction mixture can be adjusted. In particular, the pH is adjusted to between 6 and 14, preferably between 7 and 12, particularly preferably between 8 and 10, and the process is carried out at this pH.

In order to ensure a constant pH and thus constant reaction conditions, the method is carried out in particular in a buffered system. The buffer system is selected from the group consisting of aqueous solutions containing potassium carbonate, potassium bicarbonate, sodium carbonate, sodium bicarbonate, phosphates, hydrogen phosphates and / or mixtures thereof. According to the invention, it is irrelevant whether the oxidizing agent and the radical initiator are added simultaneously or successively. For example, it is conceivable that first the oxidizing agent and then the free radical initiator is added. Here, the time offset of the addition of the radical initiator is preferably 5 minutes to 20 hours after the addition of the oxidizing agent.

The preferred amount of the polymerizable monomer used with respect to the amino derivative of the general formula I is in a weight ratio of 0.1: 1 to 100: 1, preferably from 1: 1 to 20: 1, particularly preferably from 5: 1 to 15 :1.

It is also advantageous if the oxidizing agent with respect to the amino derivative of the general formula I in an amount between 0.01 and 100 wt .-%, preferably 1 to 20 wt .-%, particularly preferably between 2.5 and 7.5 % By weight is added.

The same weight ratios with respect to the amino derivative of the formula I also apply to the free-radical initiator, in particular in an amount between 0.01 and 100 wt .-%, preferably 1 to 20 wt .-%, particularly preferably between 2.5 and 7.5 wt .-% is added.

The process is preferably carried out at a temperature between 0 ^° C. and 100 ^° C., preferably between 20 and 80 ^° C., particularly preferably between 40 and 60 ^° C. In a further advantageous embodiment of the process, the temperature after addition of the oxidizing agent is set between 0 and 50 ^° C., preferably between 5 and 30 ^° C. Here is it is particularly preferred if the temperature after addition of the radical initiator is increased to 30 to 80 ⁰ C.

Preferred molar ratios of the monomeric units of the formula I are more closely characterized by the following proportions: a / (a + b + c) between 0.05 to 0.85, preferably between 0.1 to 0.7, particularly preferably between 0, 2 and 0.5 and b / (a + b + c) between 0.05 to 0.85, preferably between 0.3 to 0, 8 or b = 0.

The weight-average molar mass M _{w of} the aminoderivative of the formula I is not subject to any particular restriction. In particular may be included gomere the possibility olive, so that preferred molar masses between 20-50 '10 ³ kg / mol, preferably between 50-20 ^■ 10 ³ kg / mol, more preferably between 100-1' 10 ⁴ kg / mol are included.

It is clear from general formula I and the statements made above that the polymeric saccharide skeleton on which the formula I is based is deacetylated by starch, amylose, amylopectin, cellulose, chitosan, and / or partially deacetylated chitin (preferably from 40 to 100%). can be derived. Partially deacetylated chitins can be prepared by saponification reaction with an alkali or by chitin-deacetylase, starting from chitin. Likewise, a version of the method is conceivable in which amino derivatives of degraded polysaccharides, such as maltodextrin, can be used. Maltodextrin is known to mean a water-soluble carbohydrate mixture which is prepared by (partial) hydrolysis of starch. The hydrolysis is carried out, for example, by acid or by enzymatic means; Maltodextrin is therefore a mixture of monomers, dimers, oligomers and polymers of glucose. Depending on the degree of hydrolysis, the percentage composition differs.

Since amino derivatives of maltodextrins can be used, it is thus clear that monomeric units, as described above, can also be present in the reaction mixture. Likewise, however, the subsequent enzymatic or hydrolytic degradation of graft copolymers prepared according to the process starting from said amino derivatives is possible.

After completion of the reaction, the product is purified, preferably by chromatographic methods, or dialysis, and the product thus obtained is isolated.

It is further advantageous if the product is subsequently freeze-dried thereon.

The present invention also provides a graft copolymer which can be prepared by the method described above.

Likewise, according to the invention, a coating is provided which contains the graft copolymer.

Such graft copolymers are used in the production of coatings.

The present invention will be described in more detail with reference to the following description, without wishing to restrict the invention to the parameters executed there. The abbreviations used below are summarized in advance. The symbols designated in the experiments for the closer characterization of the Starting materials refer to the general formula I and the abbreviations designated here.

List of abbreviations

CEDEAC: chloroethyldiethylammonium chloride

DEAE: 2-diethylaminoethyl

DEAECMST: diethylaminoethyl carboxymethyl starch.

DEAEHEC: diethylaminoethyl-hydroxyethyl chitosan

DEAESPC: Diethylaminoethyl sulfopropyl chitosan

DEAEST: Diethylaminoethylstarch

DEAETMAC: diethylaminoethyl-trimethylammonium chitosan

DEAEQC: diethylaminoethyl-quab-chitosan

= Diethylaminoethyl-2-hydroxy-1-trimethylammonium N-propylchitosan EGDMA: ethylene glycol dimethylacrylate (97%, purum,

Fluka, CAS 97-90-5) HEMA: hydroxyethyl methacrylate (Fluka, Chemika

Analysis No. 304311/1 192) K ₂ CO ₃ : potassium carbonate (purum pa, 99%, Fluka,

CAS 584-08-7) LM: Solvent NaOH: Sodium hydroxide, 0.1 M (Merck, Batch / Lot:

OC 537786) NaPS: sodium peroxodisulfate (98%, acros,

CAS 7775-27-1)

NVP: N-vinylpyrrolidone (BASF) PVP: polyvinylpyrrolidone (e.g., Luviskol K30 and

K90, BASF) V50: 2,2'-azobis (2-amidinopropane) dihydrochloride

(Wako, CAS 2997-92-4) VCAP: N-vinylcaprolactam I. PREPARATION OF AMINO DERIVATIVES

For the preparation of the amino derivatives (hereinafter by way of example starch) was worked according to the following procedure. This method offers the following advantages in particular:

• homogeneous implementation,

No salt needed to suppress the starch grain swelling,

• Use of phase transfer catalyst to delay precipitation of any insoluble products.

The synthesis of the amino-modified starch derivatives takes place according to the following general reaction equation:

Depicted is the reaction of degraded starch (maltodextrin) with chloroethyldiethylammonium chloride (CEDEAC) (which is present as the result of neutralization with HCl as the hydrochloride)

General instructions (based on maltodextrin);

21.4 g maltodextrin (Glucidex 2, 0.123 mol, Roquette, M _w ~ 100-500 k) are mixed with the appropriate amount NaOH (Tab. 1) dissolved in 150 g of water. It is heated with stirring (300 rpm) to reflux conditions (60 ⁰ C). Now 3 g Tetrabutylammoniumhydro- be added and then the appropriate amount of CEDEAC (Table 1). After 7 h, the cloudy basic solution is neutralized with 0.1 N HCl, poured into water and dialyzed against water for 1 week (14 k). Finally, it is freeze-dried.

Table 1

Implementations with CEDEAC

Try equiv. (Mass) equiv (mass) DS

CEDEAC NaOH ( ¹ H NMR)

0, 1, 2 (4.25 ^g) 0.44 (2, 17 ^g) 0, 19

0 2, 4 (10.0 ^g) 0.88 (4, 34 ^g) 0, 36

3 0, 6 (10, 0 g ⁾ 1.32 (6, 49 g ⁾ 0, 50

The degree of substitution DS (per glucose unit) was determined by ¹ H NMR spectroscopy.

II. PFROPOPOPOLYMERIZATION

Comparative experiment 4; (single stage polymerization, JS 56)

In a comparative reaction with conventional single-stage initiation (with sodium persulfate only) under otherwise the same conditions as in experiment 5, the yield is only 25% and the solids content is 6.09% by weight. The experiments are always carried out with the same ratio of DEAE starch (A = O, R ¹ = H, R ² = Et, R ³ = CH ₂ OH, n = 0, b = 0, a / (a + c) ~ 0 , 43; c / (a + c) ~ 0.57) to NVP and equal mass of LM (water). Trial 5 (JS 57);

2.00 g of DEAE starch (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ OH; n = 0; b = 0; a / (a + c) ~ 0.43; c / (a + c) ~ 0.57) are dissolved with stirring in 70 ml of water in a three-necked flask. The solution is titrated to pH 9 with sodium hydroxide solution. Then 20.0 g of N-vinylpyrrolidone and 0.10 g of potassium carbonate are added. The solution is degassed for 5 minutes with a stream of nitrogen. Then, 0.100 g of sodium persulfate are dissolved in 1 ml of degassed water and syringed through the septum into the reaction vessel (t = 0). For pH control samples are taken every 30 minutes with the syringe through the septum. After 5 h 20 min reaction time at room temperature, 0.100 g of V50 (dissolved in 1 ml of degassed water) is added to the reaction solution with a syringe and the temperature is raised to T = 50 ^° C. At t = 19 h, the reaction is stopped by cooling to RT. Yield (drying balance):> 93% d. Theory. The solids content of the high-viscosity solution is 22.37 wt .-%. With a doctor (0.2 mm) films of the polymer thus prepared are mounted on a glass plate. The drying takes place in air.

Trial 6;

In a 250 mL 3-necked flask, add 2.00 g of DEAECMST (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ -O-CH ₂ -COONa; DS (R ³ ) = 0, 3 ; n = 0; b = 0; a / (a + c) = 0, 36; c / (a + c) = 0, 64) and weighed into 70.00 g dist. H ₂ O dissolved. Then 20.14 g NVP is added with stirring. The pH is then adjusted to 8-9 with 0.1 M NaOH. 0.1015 g of K ₂ CO ₃ are then added and the resulting solution is stirred for 3 min. degassed with N ₂ . The polymerization is dissolved after addition of 0.1005 g NaPS ( distilled in 1.1440 g. H ₂ O) is then stirred for 5 h at RT. Thereafter, 0.1006 g of V50 are added and heated to 50 ⁰ C for 24 hours. Yield:>90%; Solids content: 21.71% by weight (drying balance); Film formation with doctor blade (0.2 mm) on glass plate, drying in air.

Trial 7;

In a 250 mL 3-necked flask, add 1.00 g of DEAEQC

(A = NH, B = Formula III where m = 1, R ⁴ = Me, X ^" = Cl ^" , R ¹ = H, R ² = Et, R ³ = CH ₂ OH, n = 0, a / (a + b + c) = 0.21, b / (a + b + c) = 0.77, c / (a + b + c) = 0.02) and weighed into 35.0 g dist. H ₂ O dissolved. Then 10.17 g NVP is added with stirring. The pH is then adjusted to 8-9 with 0.1 M NaOH. There are then added 0.0500 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is initiated after addition of 0.0500 g of NaPS (dissolved in 0.5555 g of distilled H ₂ O), followed by stirring at RT for 5 h. Thereafter, 0.0501 g of V50 (0.5193 grams least in. H ₂ O) was added and at 50 ⁰ C for 24 h heated. Yield: 26%; Solids content: 6.27% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Trial 8:

In a 250 mL 3-neck flask, add 1.00 g of DEAETMAC (A = NH; B = - [NMe ₃ ] ⁺ Cl ^' ; R ¹ = H; R ² = Et; R ³ = -CH ₂ OH; n = 0) a / (a + b + c) = 0.37, b / (a + b + c) = 0.59, c / (a + b + c) = 0.06) and weighed into 35.11 g least. H ₂ O dissolved. Then 10.31 g NVP is added with stirring. The pH is then adjusted to 7 with 0.1 M NaOH. The resulting solution is stirred for 3 min. degassed with N ₂ and after addition of 0.0505 g of NaPS (dissolved in 0.5026 g of distilled H ₂ O) for 5 h at RT. After that are (least 0.5007 g. H ₂ O) 0.0503 g of V50 was added and heated to 50 ⁰ C for 24 hours. Yield: 33.6%; Solid content: 7.91% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Trial 9:

In a 250 mL 3-necked flask, add 1.0 g of DEAEST (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ OH; n = 0; b = 0; a / (a + c) ~ 0.43, c / (a + c) ~ 0.57) weighed into 35.0 g dist. H ₂ O dissolved. Then 10.04 g of NVP and 0.1 g of EGDMA are added with stirring. The pH is then adjusted to 8-9 with 0.1 M NaOH. There are then added 0.500 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is initiated after addition of 0.0508 g of NaPS (dissolved in 1.011 g of distilled H ₂ O), followed by stirring at RT for 5 h. Thereafter, 0.0503 g of V50 (0.5095 g in H ₂ O) was added and at 50 ⁰ C for 24 h heated. Yield: 85.3%; Solids content: 20.33% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Trial 10;

In a 100 mL 3-necked flask, add 0.5 g of DEAEST (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ OH; n = 0; b = 0; a / (a + c) ~ 0.43, c / (a + c) ~ 0.57) weighed out and in 17,50 g dist. H ₂ O dissolved. Then, with stirring, 5.01 g of HEMA are added thereto. The pH is then adjusted to 8-9 with 0.1 M NaOH. There are then added 0.0250 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is initiated after addition of 0.0251 g of NaPS (dissolved in 0.5793 g of distilled H ₂ O), followed by stirring at RT for 5 h. Thereafter, 0.0252 g of V50 (in 0.5162 g H ₂ O dissolved) and heated to 5O ⁰ C for 24 hours. Yield: 83.73%; Solid content: 19.34% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Experiment 11:

In a 250 mL 3-necked flask, add 1.02 g DEAEST (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ OH; n = 0; b = 0; a / (a + c) ~ 0.43; c / (a + c) ~ 0.57) and distilled into 35.03 g. H ₂ O dissolved. Then stir

Add 3.92 g NVP and 0.0345 g EGDMA. The pH is then adjusted to 8-9 with 0.1 M NaOH. There are then added 0.0502 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is initiated after addition of 0.0500 g of NaPS (dissolved in 0.5433 g of distilled H ₂ O), followed by stirring at RT for 5 h. Thereafter, 0.0503 g of V50 (dissolved in 0.5988 g of H ₂ O) are added and heated to 50 ⁰ C for 24 hours. Yield: 46.11%; Solids content: 5.60% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Experiment 12:

In a 250 mL 3-neck flask, add 1.00 g of DEAESPC (A = NH; R ¹ = H; R ² = Et; R ³ = -CH ₂ OH; n = 0; B = Formula IV where m = 3; y ⁺ = Na; a / (a + b + c) = 0.24, b / (a + b + c) = 0.4, c / (a + b + c) = 0.36) weighed in and 70 , 02 g dist. H ₂ O dissolved. Then with stirring 10.55 g NVP is added. The pH is then adjusted to 9 with 0.1 M NaOH. There are then added 0.0503 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is initiated after addition of 0.0511 g of NaPS (dissolved in 0.5101 g of distilled H ₂ O), followed by stirring at RT for 5 h. Thereafter, 0.0513 g of V50 (dissolved in water) added and heated to 50 ⁰ C for 24 h. Yield: 14.06%; Solid content: 1.98% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Trial 13:

In a 250 mL 3-neck flask, add 2.04 g of DEAECMST (A = O; R ¹ = H; R ² = Et; R ³ = -CH ₂ -O-CH ₂ -COONa; DS (R ³ ) = 0, 3, n = 0, b = 0, a / (a + c) = 0.36, c / (a + c) = 0.64) and weighed into 70.0 g dist. H ₂ O dissolved. Then 20.39 g NVP and 0.20 g EGDMA are added with stirring. The pH is then adjusted to 8-9 with 0.1 M NaOH. There are then added 0.1003 g K ₂ CO ₃ and the resulting solution for 3 min. degassed with N ₂ . The polymerization is after addition of

0.1003 g NaPS initiated, then stirred for 5 h at RT. Thereafter, 0.1027 g of V50 (in 1.013 g of H ₂ O) was added and at 50 ⁰ C for 24 h heated. Yield: 91.15%; Solids content: 21.83% by weight; Film formation with doctor blade (0.2 mm) on glass plate.

Trial 14; Polymerization of VCAP

Typical Reactions (2g DEAEST (A = O; R ¹ = H; R ² = Et; R ³ = CH ₂ OH; n = 0; b = 0; a / (a + c) = 0.42; c / ( a + c) = 0.58), 70 g water, 20 g VCAP, titrated to pH 9, 0.1 g of potassium carbonate as a buffer) were incubated at 50 ⁰ C with 0.1 g sodium persulfate in 2 ml of water ini tiiert (see below Scheme). Then, after 1 h, 0.1 g of potassium carbonate were added. After a total of 5.5 hours, 0.064 g of V50 in 2 ml of water was added. After a total of 19.5 h reaction time was stopped and the reaction mixture was freeze-dried. The yield was 50%.

III. FILMING FEATURES

Of the polymers prepared above, films were prepared on a glass plate and dried. All sample experiments 5 to 14 were adjusted to a solids content as described in experiment 5 (22.37 wt.%). The solutions were applied with a doctor blade (0.2 mm) on glass plates and then dried at 80 ⁰ C for 2 h.

All films shown in the invention were distinguished by excellent transparency and by negligible cracking and blistering. All other samples and blends showed more or less pronounced blistering and cracks after drying.

It was thus possible to show that the starch-graft copolymers prepared by the 2-stage initiation process have distinct advantages over blends and / or blends.

Claims

claims A process for the preparation of polysaccharide graft copolymers starting from at least one amino derivative of a polysaccharide and / or a mixture containing at least one amino derivative of a polysaccharide, wherein the amino derivative has the general formula I.

Formula I being Oxygen, NR ⁴ or [N (R ⁴ ) ₂ ] ⁺ / X ^~ is, with R ⁴ independently of one another selected from the group consisting of hydrogen, linear or branched C ₁ -Ci ₂ -AIkIyI-, Ci-Ci ₂ alkenyl -, Ci-Ci ₂ - alkynyl, C ₇ -C ₁₈ aralkyl, C ₆ -C ₁₈ aryl, C ₆ -C ₈ - heteroaryl and / or -C (O) - (CH ₂ ) _X -CH ₃ with x = 0 to 11, where X ^"is a negatively charged counterion, R ^{1 is} independently selected from the Group consisting of hydrogen, linear or branched _Ci-C12 alkyl, _Ci-Ci2 alkenyl, Ci-Ci ₂ - ryl- alkynyl, C ₇ -C ₈ aralkyl, C ₆ -C ₈ -aryl, heteroaromatics, hydroxy, Ci-Ci ducks ₂ alkoxy, amino substitution, and / or two radicals R ¹ two vicinal carbon atoms together form a ring which can be aliphatic or aromatic and may contain hetero atoms and having 1 to 8 ring members, R ^{2 is} independently selected from the Group consisting of linear or branched Ci-C ₁₂ alkyl, C _x -Ci ₂ alkenyl, C ₁ -C ₁₂ -AlkIrIyI, C ₇ - Ciβ aralkyl substituents and / or two radicals R ² together form a ring, the is aliphatic, may contain heteroatoms and 1 to 8 Having ring members, R ^{3 is} independently selected from the Group consisting of -CH ₂ OH, -CH ₂ OR ^4, -CH ₂ O- (CH _{2) m} -COOH, -CH ₂ O- (CH _{2) m} -COO ^~ y +, -CH ₂ O- (CH ₂ ) _m -0H, in each case with m = 1 to 12, -COOH, -COO ^" Y ⁺ wherein Y ^{+ is} a positive charged counterion, -COOR ⁴ , where R ⁴ corresponds to the definition given above, or a -CH ₂ O- Group represents the α-1,6 glycosidic with another Amino derivative of general formula I, n is 0 to 10, B is independently selected from the Group consisting of - [N (R ⁴ ) ₃ ] ⁺ / X ^" , or groupings of the formulas II, III or IV

II III IV wherein A, R ¹ , R ⁴ , m, X ^" and Y ^{+ have} the abovementioned meaning, each independently of one another the ratio of a / (a + b + c) between 0.01 and 0.95, the ratio of b / (a + b + c) between 0 and 0.9 and the ratio of c / (a + b + c) between 0.05 and 0.99 and the underlying monomeric saccharide units of the amino derivative of the formula I can also be linked to one another glycosidically in the manner illustrated and α-1,4- or β-1,4 and may also be present as monomers in the mixture, characterized in that the amino derivative of the formula I is mixed with at least one to be grafted, free-radically polymerizable monomer and an oxidizing agent is added in combination with a radical initiator. 2. The method according to claim 1, characterized in that the at least one monomer contains a vinyl group. 3. The method according to any one of the preceding claims, characterized in that at least one monomer selected from the group consisting of vinylpyrrolidones, in particular N-vinylpyrroli- Don; Alkylene glycol di (meth) acrylates, especially ethylene glycol diacrylate; alkylenes; (Meth) acrylates; acrylamide; Styrenes, - vinyl lactams, in particular N-vinylcaprolactam and / or mixtures thereof, is used. 4. The method according to any one of the preceding claims, characterized in that an oxidizing agent selected from the group consisting of hypochlorites, permanganates, peroxodisulfates such. Sodium persulfate, peroxides, peroxides, superoxides and / or hydrogen peroxide is used. 5. The method according to any one of the preceding claims, characterized in that at least one free radical initiator selected from the group consisting of azo initiators is used. A method according to the preceding claim, characterized in that the radical initiator is selected from the group consisting of - hydrophilic azo initiators, e.g. 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazoline -2-yl) propane] dihydrate dihydrate, 2,2 'azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2'-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis (1-imino -l-pyrrolidino-2-ethylpropane) dihydrochloride, 2.2 "azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] -propionamide}, 2,2'-azobis [2-methyl-N- (2-hydroxyethypropionamide]; lipophilic azo initiators, such as, for example, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2 methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2-methylpropionitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2 ' Azobis [N- (2-propenyl) -2-methylpropionamide], 1- [(1-cyano-1-methylethyl) azo] formamide, 2,2'-azobis (N-butyl-2-methylpropionaraid), 2, 2'-azo-bis (N-cyclohexyl-2-methylpropionaraid); Macroazoinitiators, e.g. polysiloxane, polyethylene glycol and / or diazo compounds based on their block copolymers formed with vinyl monomers, preferably having a weight-average molecular weight of between 500 and 20,000 g / mol); and / or mixtures thereof. 7. The method according to any one of the preceding claims, characterized in that the process is carried out in water. 8. The method according to any one of the preceding claims, characterized in that at least one base is added. 9. The method according to the preceding claim, characterized in that the at least one base is selected from the group consisting of sodium hydroxide, potassium hydroxide, and / or mixtures thereof. 10. The method according to any one of the preceding claims, characterized in that the method is carried out at a pH between 6 and 14, preferably between 7 and 12, more preferably between 8 and 10. 11. The method according to any one of the preceding claims, characterized in that the method is carried out in a buffered system. 12. The method according to the preceding claim, characterized in that the buffer system is selected from the group consisting of aqueous solutions containing potassium carbonate, potassium bicarbonate, sodium carbonate, sodium bicarbonate, phosphates, hydrogen phosphates and / or mixtures thereof. 13. The method according to any one of the preceding claims, characterized in that the Oxidati- onsmittel and the radical initiator are added simultaneously and / or sequentially. 14. The method according to any one of the preceding claims, characterized in that first the O xidationsmittel and subsequently the radical initiator is added. 15. Process according to the preceding claim, characterized in that the addition of the radical initiator takes place for 5 minutes to 20 hours after the addition of the oxidizing agent. 16. The method according to any one of the preceding claims, characterized in that the at least one polymerizable monomer with respect to the amino derivative of the general formula I in a weight ratio of 0.1: 1 to 100: 1, preferably from 1: 1 to 20: 1 , more preferably from 5: 1 to 15: 1 is used. 17. The method according to any one of the preceding claims, characterized in that the at least one oxidizing agent with respect to the Aminoderiva- Tes of the general formula I in an amount between 0.01 and 100 wt .-%, preferably 1 to 20 wt .-%, particularly preferably between 2.5 and 7.5 wt .-% is added. 18. The method according to any one of the preceding claims, characterized in that the at least one radical initiator with respect to the amino derivative of general formula I in an amount between 0.01 and 100 wt .-%, preferably 1 to 20 wt -.%, Particularly preferably between 2.5 and 7.5 wt .-% is added. 19. The method according to any one of the preceding claims, characterized in that the method at a temperature between 0 ⁰ C and 100 ⁰ C, preferably between 20 and 80 ⁰ C, more preferably between 40 and 60 ⁰ C is performed. 20. The method according to the preceding claim, characterized in that the temperature after addition of the oxidizing agent between 0 and 50 ⁰ C, preferably between 5 and 30 ⁰ C is set. 21. The method according to any one of the preceding claims, characterized in that the temperature after addition of the radical initiator is increased to 30 to 80 ⁰ C. 22. The method according to any one of the preceding claims, characterized in that the ratio a / (a + b + c) between 0.05 to 0.85, preferably between 0.1 to 0.7, more preferably between 0, 2 and 0, 5 lies. 23. The method according to any one of the preceding claims, characterized in that the ratio b / (a + b + c) is between 0.05 to 0.85, preferably between 0.3 to 0.8, or b = 0. 24. The method according to any one of the preceding claims, characterized in that the degree of substitution of the radical R ^{3 is} between 0.1 and 0.95, preferably between 0.25 and 0.65 or 0. 25. The method according to any one of the preceding claims, characterized in that weight-average molar mass M _{w of} the amino derivative of the formula I between 20-50 "10 ³ kg / mol, preferably between 50-20 ^■ 10 ³ kg / mol, particularly preferably between 100-1 '10 ⁴ kg / mol. 26. The method according to any one of the preceding Ansprü- che, characterized in that the product is purified after completion of the reaction by chromatographic methods, in particular by dialysis and / or isolated. 27. The method according to any one of the preceding claims, characterized in that the product is freeze-dried. 28. Polysaccharide graft copolymer, preparable according to one of the preceding claims. 29. Coating comprising a polysaccharide graft copolymer according to the preceding claim. 30. Use of the polysaccharide graft copolymers according to claim 28 for the production of coatings, wraps, films and / or films.