WO2018009989A1 - Process for obtaining nanocomposites of poly(l-lactide) without inertization or solvents - Google Patents

Abstract

The present invention relates to a process for obtaining nanocomposites of poly(L-lactide) by in situ ring-opening polymerization without inertization of the reaction medium or use of a solvent. The present invention is different in that it is based on the elimination of the inertization step, the fact that solvents are not used, and the fact that clay is added slowly and continuously, providing a simplified process, with improved homogenization between the filler and the polymeric matrix, and avoiding the release of toxic agents to the environment. The present invention pertains to the field of chemistry and more precisely to the area of biomaterials for fabric and packaging engineering.

Description

 PROCESS FOR OBTAINING: NON-COMPLIANCE POLY ■ LACTIDE) WITHOUT INERTXSATION AND CAKPO SOLVENTS GIVES INVENTION

 This invention relates to the field of chemistry, more specifically to the field of tissue and packaging engineering biomaterials, discloses a process for obtaining poly (L-lactide) (PLLA) nanocomposites, including use of reaction medium inert gas: in solve t s.

 BACKGROUND OF THE INVENTION

 Biomaterials

 Synthetic materials used in biological (biomaterial) applications may be classified as metals, ceramics, polymers and composites.

 Traditionally synthetic polymers are designed and manufactured to have long term stability. From 1970 on, controllable life-time biodegradable polymers have received widespread attention as biomedical materials and consumer products that are compatible with the environment in which they are applied.

This class of biomaterials has two main advantages when compared to non-biodegradable biomaterials. The first advantage is that they do not cause permanent foreign body reactions, as these materials are gradually absorbed ¹ by the body and leave no trace of residues: permanent in the places where the implants were performed. The second advantage is that some specific types of biomaterials are capable of regenerating tissues through their interaction with immune cells. Based on the behavior of polymeric bioreactors in living tissues, they can be divided into biostable, bioabsorbable, partially bioabsorbable, or bioreactors.

 In many cases bioraaterals are required for a short time and in these cases, bioabsorbable, partially bioabsorbable or fooreactive materials are more appropriate than biostable polymeric materials. Thus, the bioabsorbable or bioreactive surgical materials are suitable for temporary internal fixation when the tissue has been traumatized, as the implant preserves the tissue structure in its early healing phase, such as bones, tendons or skin. As the implant gradually decomposes, the stresses are also gradually transferred to the healing tissue. The time required depends on the type of matter, molar mass and structural properties, as well as where the implant is inserted.

 Many synthetic polymers are considered bioabsorbable or more resorbable in living tissues. The most important surgical bioresorbable polymers are aliphatic polyesters (polymers and copolymers derived from the hydroxy acids. Most of them are thermoplastic polymers, partially crystalline or fully amorphous.

 [008] 1 Table 1 shows some synthetic and natural polymers.

 Table 1: Examples of synthetic and natural polymers used as biornaterials.

"Sxpo Folimè the Poly (glycolic acid)

 Synthetic Poly Lactic Acid)

 Poly (ethylene glycol)

 Collagen

 Hyaluxonic Acid

 Natural

 Alginatc

 Agarose

As stated above, the mechanical properties and the degradation time as a function of the application needs ¹ is what will determine the type of polymeric material to be used.

 Poly (K-hydroxy acids)

f 010] Among the bioresorbable polymers poly (lactic acid) is among the few clinically used. The interest in these types of polymers is the fact of them have already approved for a number of clinical applications by the US Food and Dr g Administration {FDA) _t body responsible for the release of food and drugs in the US.

 [011] The range of applications of these polymers is vast and are employed as devices in implants, suture materials, prostheses, orthopedic repair materials, intraocular pins, and in controlled drug release.

 [012] Poly (lactic acid) (PLA) is expected to have a wide range of applications from use with biodegradable plastic, but also as a material for biomedical applications, because of its excellent mechanical properties and for being highly hydrolysable in the human body.

[013] PLA can be prepared by two types. polymerization methods: direct condensation of lactic acid and ring opening polymerization of the cyclic lactide dimer.

Both lactic acid and cyclic dimer lactide have chiral carbons, and lactic acid has two stereoisomeric forms, L- and D-lactic acid. The lactide _. , what. is the cyclic diester of lactic acid, has four different isomers: L-lactide, D-laetid the racemic mixture D, L-lactide and the optically inactive mesoacid. High purity mesolactid is difficult to prepare and is therefore rarely mentioned in the literature.

 [G5] Ring opening polymerization leads to the formation of polymers of higher molar mass than those formed by polycondensation of lactic acid. However, synthesis from lactide has the drawback of high production cost, as lactide is an expensive product.

 [016] Lactic acid may be a precursor to totally amorphous materials as well as highly crystalline materials. Poly (L-lactic acid) is a semi-crystalline polymer with melting temperature (Tm) of about 180 ° C. D-poly (lactic acid) has the same properties as L-poly (lactic acid; OD, L-poly (lactic acid) to attic is an amorphous material with glass transition temperature between 45 ° and 60 ° C). D, L-poly (lactic acid), which contains long blocks of D and L units, may have similar properties to those of optically pure polymers.

[017] Poly (L-lactic acid) as well as its lactitic cyclic dimer, shows good mechanical strength, thermal plasticity, processability and can undergo chain disruption in the body: human resulting from oligomers and finally monomeric units of lactic acid, which are fully resorbable as a natural intermediate to metabolism, in particular L-isomer is a biological metabolite of the human body.

 Polymeric Nanocomposites

 Pallimeric kanocomposites are defined as materials composed of more than one phase where at least one of the constituents of one of these phases, commonly a nanocharge, has a nanometric dimension (1-100 nmj) and its properties exhibit substantial improvement.

 [019] The nanoscale loads used in the polymers produce composite materials with improved mechanical, electrical, ethical, thermal and magnetic properties.

 [020] By definition, all clays are made up of crystalline particles from a limited number of known minerals such as "clay minerals".

 [021] Clay minerals which are part of the group of 2: 1 phyllylicates are mainly made up of monmormononite, beidelite, nontronite, volconscoite, saponite, sauconite, hectorite. They consist of two sheets of tetrahedral silicate, with an octahedral central leaf, joined together by common oxygen to the leaves. These sheets are continuous in the directions of axes a and b and are stacked randomly on top of one another in some types and in some order in others.

[022 For these clays in Brazil are also The terms bentonite are used and without any information as to the geological origin or the mineral mineral composition.

 Since montinorilonite has the highest swelling capacity in aqueous medium, it is a great option for obtaining polymeric compounds.

 However, like most polymers, thus, like P¾, they are organophilic, and the swelling capacity of montmorillonite makes it extremely hydrophilic, the interaction between montinorilonite and polymer matrix is very low. Organizing the bentonites becomes extremely necessary for obtaining polymeric nanocomposites.

 [025] In general. Polymerization processes, including the process of obtaining the poly L ™ Lactldec, comprise a step of inerting the reaction medium to avoid counting with 0; and, when the process is in solution, the addition of solvent: these steps may require time, use of specific equipment and also promote the emission of toxic agents to the environment.

In view of the foregoing, the present invention relates to a process for obtaining a poly. (L-Lactide) comprising ¹ the addition of nanocarb of clay after complete fusion of the monomer and without the use of inertia gas from the reaction medium and solvent, producing a material that can be applied as a biomaterial.

 PA TECHNICAL STATE

[027] The document entitled "Influence of Experimental Parameters on Poly (1-Lactic Acid) Synthesis", by the name of Ligiane Alin Inhoato, refers to the synthesis of Poly (1-Lactic Acid) and evaluation of the influence of various factors such as temperature, catalyst concentration, use of nitrogen gas and also non-inertization of the medium. After each document, perform the synthesis of the PLLA without. The use of nitrogen does not conflict with the present invention, since its synthesis occurs in ampoules and does not use the addition of nanocharge, which gives a material with characteristics completely different from those synthesized in the present invention.

 [023] Document C 161887 entitled "Polyacryl lactide / fatiy polyester nano-cO posite material and preparation etivod and applloation", refers to a biocompatible and biodegradable PLA nanocomposite and its process by polymerization of monomers of lactide. However, the material obtained in such a document has a completely different concept from the present invention, since it does not use an inorganic filler but rather a polymeric matrix, in addition to the use of another polymer as nanocarbon.

 [029] The document entitled "Synthesis and Characterization of PLLA ep (lla-co-cl} obtained in Solution Polymerization Reactions" in the name of Souza, EC, et al., Refers to a PLLA synthesis process. and P ILLA-co-CL) by solution polymerization: Completely to the present invention, the PLLA described herein is obtained in toluene solution and reaction medium inertization, and does not use nanocarbons. Furthermore, the use of toluene solvent for the synthesis of PLLA makes the process described in such a document unviable industrially.

[030] The document entitled "Synthesis and ^■ Characterization of poly (lactic acid) not as biomaterial "in the name of Vanusa Daioso jahno, refers to a synthesis of PLA through direct polycondensation and was somewhat supercritical, through routes that seek a clean, organic solvent-free polymer synthesis process The syntheses of PLLA performed in such a document use supercritical pressure methodology, which is a different procedure from that of the present invention. since the synthesis of PLLA takes place through the dimer which is carried out in an ampoule and the addition of the catalyst occurs after monomer fusion.In the present invention, quite distinctly, the catalyst is added together with the monomer and after fusion. of the material and the addition of the nanocarbon slowly and continuously without the reaction medium being inerted.

[031] The document entitled "Synthesis of Polylactids / Clay Nanccomposites Hy in situ Intensive & Polymeric Polymerization in Carbon-4oxide" in the name of Urbanczyk, Laetitia et al., Refers to the process of obtaining PLA by polymerization with carbon dioxide. supercritical it. In such a document, the synthesis of PLLA nanocomposites utilizes supercritical medium. In this synthesis the monomer and nanocarbon are added in one step and then the catalyst is added and the pressure increases using CO-z where the polymerization process is started. Quite differently, in the present invention, the monomer and the catalyst are added to the reaction without intermingling the reaction medium and the nanocarbon is added after melting of the monomer slowly and continuously. Therefore, unlike the state of the art, the present invention suggests a simpler process of obtaining PLLA nanocomposites without the use of inerting gas and pressure increase without the use of any solvent: in the reaction medium, besides allow the slow and continuous addition of nanocargo allowing better homogenization of the charge with the polymer matrix, further simplifying the process and avoiding the emission of toxic agents into the environment.

 BRIEF DESCRIPTION

[033] The present invention relates to a process for obtaining poly (L-lactide) (PLLA) iranocompounds using: the I-Laetrdeo monomer by ^: ring opening polymerization in situ without inertization and without use of solvents,

 BRIEF DESCRIPTION OF THE FIGURES

 FG 1 shows 03 JTTIR spectra for PLLA / Clay nanocomposites synthesized using the in situ p-ligation process with reaction medium inertization;

[03.5] to FIG. 2 shows the FTI spectra for the PLL & Clay nanocomposite synthesized using the in situ polymerization process without inertization of the reaction medium;

_. [0.36 ·] FIG. 3A shows the G curves referring to thermogravimetric analysis of the three PXL polymers with reaction medium inertization and clay addition;

[037] FIG. 3B shows the DTG curves for the terraogravimetric analysis of the three PLLA polymers with the reaction medium inertization and clay addition. 1038] The Fie. 4A shows the TG curves for the radiographic analysis of the .PLLA polymer without inerting the reaction medium with clay addition.

[039] FIG. B ^; shows the DTG curves .Referring to thermographic analysis: of PLLA polymer without inertization: of reaction medium with clay addition

 [040] The F1G. SA shows DSC curves for second heating performed for NanoPLLA 1 polymer synthesized with medium: reaction inertization;

 [041] FIG. 5B shows, a. DSC curve. referring to the second heating performed for the Nano PLLA 2 polymer synthesized with reaction medium inertization;

 [042] The FI. 5C shows the DSC curve for the second heating performed for the NanoPLLA 3 polymer synthesized with reaction medium inertization;

[043] FIG. 5D shows the DSC curve for second heating ¹ performed for NancPL.LA polymer 4 ^: synthesized without inertization: reaction medium;

: [044 ^'j FIG. 5E shows the DSC curve for the second heating performed for PLL9 polymer synthesized without addition of clay; and

[045] FIG. 6 shows the diff atograma the x-ray NanoPLLA 4 using sation polymerization process without inerting and compared: the one obtained for the Algiers organophilizated CN-40 with 12 to inododecanó ^acid: acid.

 DESCRIPTION PET¾IiH¾D & D¾ IKYBNÇ & O

[046] A, the present invention describes a process for obtaining polymer (L-lactide} nanocomposites by in situ ring opening polymerization without reaction medium inertization, comprising the following solvents: following: steps;

a) heating the reactor until reaching a temperature ranging from-2Z0 and 12G¾ C, preferably 140 ^'; C and keep heating until the end of the process;

 ) add the L-lactide inonomer, then add 0.51 to 4.0%: of a catalyst belonging to the group of titanium IV alkoxides, preferably 1.5 of the tin octanoate catalyst and then add 5 to 80 µl primer belonging to the protieog solvent group. preferably, the 1-dodecancl to the reactor under agitation was a range ranging from 2700 rpm to 5000 rpm, preferably 3000 rpm, until complete melting;

 c) adding filler of organophilic clay, preferably 12-aminododecanoic acid organofluorinated bentonite, in a proportion of 1.0 to 12% of the amount of monomer used in the synthesis, under continuous agitation and slowly and continuously, and not to be added just one time ;

 d) keep stirring for 15 to 40 minutes until nomination with 1eta;

 e) keeping at rest for 1 to 12 hours, still under heating, until the end of polymerization according to the desired molar strain;

 Tatilated materials

 Bentonite clay

 [047] One has been chosen. bentonite clay, commercially known as Algiers C-40 (natural sodium clay; Table 2 shows the analytical characteristics of the clay studied.

Table 1: Analytical Characteristics of Clay

 Before Organizers

[0 8] Modification of bentonite clays is a key point for: application of this material in polymeric matrices, as the use of: modifying agent (organophilizing agent in the case of organophilic clays; suitable may significantly alter the intercalation length of the between the interlabellar spacing of the clay due to the interaction between polymer and the functional groups of the modifying agent.

 Hydrochloric acid

 For the organophilization: of the clay using the organofilizant agents was used hydrochloric acid P. THE. for the acidification of the medium and protonation of 12-aminododeeanic acid & octadeylamine, thus enabling the exchange of cations ...

 ? LL¾ Nanocomposite Synthesis

 For the synthesis of PLL nanocomposites the L-Lactide monomer, the tin catalyst ootanoate (95% purity) and the 1-dodecanol initiator (98% purity) were used. The clays used as nanocarbons were obtained through the organophilization process.

The use of bentonite clay with the use of acid 12 ^:

For the process of organofilization of the bentonite clay a soil disperser was used. In this process, 600 ml of distilled water at a temperature of 100 ° C to facilitate the solution of the amino acid was placed in the soil disperser container. and then 25 g of clay was slowly added to the vessel under constant stirring at a speed of S000 rpm. After complete addition of the clay, the stirring speed was increased to 12000 rpm and kept constant for 2 ^: 0 minutes for complete clay dispersion.

To a beaker was added 100 l of distilled water at 80 ° C, 2.9 mL of PA, 6.23 ^: amino acid hydrochloric acid. The function of the addition of hydrochloric acid in this The procedure is for protonation of the amino acid to occur and to acquire a positive charge, making possible the process of changing clays in the clays. The amount of amino acid used is dependent on its molar mass and cation exchange capacity of the clay used. The amino acid solution was then added to the dispersion of the clay under constant agitation at a rate of ¾QQ0 rpm.

 After complete addition of the amino acid solution, the mixture was stirred at 9000 rpm for 20 minutes. After this period, the stirring speed was increased to 12000 rpm and held for 10 minutes. The mixture was then transferred to a poker where it was left to stand for 24 hours at room temperature. After this period, vacuum filtration was performed using a Bucbner e-itate funnel to remove excess exits. In this step, 2000 mL of distilled water was used to wash the material.

[054]; The material was oven dried at a temperature of 60 ± 5 ° C for a period of 48 hours and then macerated in mortar and sieved in ^a 200 - 0.07 mm ABNT sieve).

 Sents of PLLR Nanocomposites by In sxtn Ring Opening Polymerization

[055] The reactor silicone bath was kept at a constant temperature: 140 ° C. In the reaction vessel were added 50g of L-Lactide monomer, 0.5 to 4.0%, preferably 1.5% of Tin Octanoate catalyst and 5 to 80 pL, preferably 57 μΐ, of 1- Dodecanol primer. The monomer, catalyst and initiator were constantly stirred within a range of 2700 rpm to 5000 rpm, preferably 3000 rpm, until complete melting. After total fusion of the monomer, the addition of 12--3ml & dodecan-oic acid organophilized benonite was started in the ratio 1.0 to 12%, preferably 0.5% of the amount of Kionomer used in the synthesis, under stirring. goes on and on and on and on. Stirring was continued for 15 to 40 minutes until complete homogenization. After complete addition to the beginning of the viscosity increase, stirring was removed and kept at rest for 1 to 12 hours, preferably 1 hour, still under heating, until the end of the polymerization.

 For the process without inertization and slow addition of clay, complete homogenization between the polymeric matrix and the clay was verified (Algiers CN-40 organophilized with l2-amiriQd.odecanoic acid). This process facilitated the dispersion of the clay, since its addition occurred after the monomer fusion and slowly, resulting in better homogenization and allowed a greater interaction between the clay and the growing polymeric matrix.

 Characterization of the PLIA KanoGòmpósi.tos

[057] Synthesized nanocomposites were characterized using infrared absorption spectroscopy (FTIR), thermogravimetric analysis (T.GA), differential scanning calorimetry (DSC) and X-ray diffraction (DR-X) techniques. By way of comparison only, the results of the FTIR, TGA, DSC and DR-X techniques are shown for both PI.LA nanocomposites synthesized using the in-situ polymerization process without reaction medium inertization. ^: using the unsuccessful polymerization process with inertization of the reaction medium. Additionally, both results are compared to the polymer: PILA 9 synthesized under the same conditions.

 Gourier Transform Infrared Absorption (FTIR) Spectroscopy of PLLA Nanocomposites and g <3A,

 [059] The FXGs. 1 and 2 show the FTI spectra of the synthesized polymers to obtain the nanocomposites.

[060] Analysis of FIQ spectra. 1 and 2 indicate that the absorptions in the range of 3000 - 2900 cm ^-1 refer to the stretching of CH group bonds. and CH¾¾, the strong absorption peak around 1.7-6D cm.-1 refers to the C ~ 0 stretch stretching from the COO group, while the absorption in the 1455 - 1360 car * region and to the deformation of CH group bonds. and CH.?,. The region of 1216 - 1185 crr ¹ refers to the stretch of the C-0 bond from the COO group and at approximately 1100 cm- ^{3 it} is possible to verify the stretch of the C-0 bond from G-OH

[061] As PLLA has FTI abso- sions in regions similar to bentenitic clay (around 1100 cm- ¹ which refers to asymmetric stretching of bentonite Si-0 bond) no ^{: it} was possible to verify through this technique whether there was interaction between polymer and clays in synthesized materials.

 Thermo-gravitational Analysis (G¾) of the Nanocomposites of

[0:62] for all polymers obtained with nanoarga addition, thermal stability was determined by TGA analysis. Figures 3 & 3B present the TGA analyzes obtained.

[063] Table 3 shows the initial mass loss temperature (Ti)., Degradation temperature (Τ _; > .. ¾), and mass loss final temperature (T>) for the polymers produced with the addition. of clay with and without inertization of the reaction medium and which refer to the thermogames present in FIGS. 3¾, 3B and 4,4B.

 Table 3: Temperatures obtained from thermal degradation for PLLA polymers without inertization of. reaction medium and clay addition, and PLLA9 polymer produced without clay addition.

[064] Analyzing the results presented in F Gs. 3.A, 3B and 4A, 4B and Table 3 it can be seen that for PLLA polymers with clay addition with both inerting and non-inerting the reaction medium there is a single mass loss profile. It is possible to notice a slight increase in the values obtained from the maximum mass loss temperatures (Tmax) and final mass loss temperature (Tf) for the polymer synthesized with the clays when compared to the values obtained from PLLA 9 (which was synthesized under When the interplay between the clay and the polymeric matrix occurs, an improvement in the thermal stability of the obtained polymers is expected, as the clay has a barrier effect on the decomposition of the polymer. compare the stability térroi ca .resultados shown in Table 3 for the four polymers with addition of clay to the result of PLLA 9, which has the same synthesis conditions (T equal to 29Q "C and _t equals 315 ° C, it is possible to observe an increase in Tmax and Tf values, indicating that some kind of interaction has occurred between the polymeric matrix and the added clays.

 Although these results indicate that there was some interaction between the matrix: polymer and the clays used, it was visually clear that this interaction did not occur effectively (phase separation) for the polymers anoPLLAÍ, NanoPLLA 2 and KanoPLLA3.

 Differential Exploratory Caloriittetri (PSC) of PLIA ytocomposites

 [066] The E'IGs. SA-5P presents the DSC graphs of the second heat for the clay-added PXilA polymers using the colorless processes and inertization of the reaction medium. By way of comparison, FIG. 5E presents the DSC graph of the second heat for the PLL & 9 polymer synthesized in clay addition.

[067] Table 4 shows the values of glass transition temperature (T} ;, Melting temperature (T _;;;) and cold crystallization temperature _(t:,:) for all polymers synthesized PLLA and using the processes with and without inertization of the reaction medium, and the polymer synthesized without the addition of clay.

table 4; Τ¾, · T _K and for the clay-added PLLA produced polymers using the two reaction processes as well as the PLLA9 polymer produced without addition. Polymers ¾ ° C) ¾, (° C) T _cc (° C)

NanoPLIA 1 (with N ₂ ) 51.0: 2.164.84, 5.14

 NanoPLLA 2 (with N2) 56 ,, Q4 172, 71 98, Ll

 NanoPLlA 3 (with N) 51.80 171, 96 91, 25

NanoPLIA 4 (no N _s) 43.80 3.71 27 92 13

 PL1A9 55, 96 174, 59 110, 13

[068] There is analyzing the results shown in Table 4, the "ranged from 43 ° C to 80 ° C and 56.04 T _m ^and C varied between 164 and 172 ° C. All polymers showed cold crystallization peak. Is it possible to verify that there was a tendency to decrease the T <: of the four polymers produced with the addition of clay compared to T. _? at 55.98 ° C for PLLA 9 (same conditions: synthesis). This fact can be attributed to two factors, mainly: the first due to the possibility that the organophilizing agent can act as a plasticizer and alter the organization of the polymeric chain and; The second is a possible decrease in polymer molar mass due to hydrolysis of the organic bentonite modifier. In the case of: PLLA 4, as the reaction time was only 1 hour, it is believed that the molar mass of this polymer is lower than that obtained for the other three syntheses performed.

 [069] It is also possible to verify the formation of a peak fusion shoulder for NanoPLLA 1, 3 and 4. This may be due to the heterogeneity of the size of the crystals that the clays provide to the polymer matrix, and these are smaller crystals. melt at lower temperatures and higher melts at higher temperatures, thus indicating the interaction of clay with the polyphthalic matrix «

X-ray Scanning (DRX) As mentioned above, the polymers NanoPLLA 1, NanoPLLA 2 and NanoPLLA 3 visually presented phase separation between the clay and the polymer phase; Thus, it can be concluded that there was no formation of nanocomposites, but. A small interaction between the clay is the polymeric matrix as seen in the characterization of the materials discussed above. By modifying the reaction process PLLA 4 was produced with the addition of 12-aminoacdecanoic acid organophilized clay (with only 1 hour reaction) and no visual phase separation was detected between the clay and the polymeric phase and therefore will be presented. DRX result only for NanoPLLA 4 ·.

[071] Due to its ease and feasibility, the XRD technique is commonly used to verify the structure of a nanocomposite. By monitoring the position, shape ¹ and intensity of the basal reflection distributions of the silicate layers, the structures of a nanocomposite. {interspersed or exfoliated} can be identified.

[072] FIG. 6 presents the diffractogram for PLLA 4 and its comparison with that obtained for argel CN-40 orga clay _. nofili zatía with 12-arcd.nododecanoic acid.

[0731 When broken nanocomposite is formed, extensive separation of the clay lamellae associated with lamellar delamination of the original silicate in the polymeric matrix results in the disappearance of any X-ray diffraction of the silicate lamellae. On the other hand, a nanocomposite intercalated, the finit lamellar expansion associated with polymer intercalation will result in a new basal reflection ¹ corresponding to the largest lamellar spacing,

 Thus, the analysis of FIG. 6 and the results of the other characterization techniques indicate the rotation of the leaf-slab nanocomposite, since any χ-ray diffraction of the lamellae has disappeared. silicate (clay).

[075] While the invention has been described anipl.amente is obvious to those skilled in the art that various changes and modifications can ^'be made in order aprimorament design without these modifications are not covered by the invention escopo-.

Claims

1. Process for obtaining poly(L-actide) nanocomposites by in situ ring opening polymerization characterized by the fact that it is carried out without a. ine fixation of the reaction medium and without addition of solvents, and also understand the following steps: a) heat the reactor; b) add L-Lactideo mortar c) add 0.5% to 4.0%, preferably 1.5% of one. catalyst belonging to the group of titanium alkoxides IV; d} add 5 to 80 μ¾., · preferably 57 ul of initiator belonging to group d protic solvents/s; e) keep the reactor under action until complete merger; f) add organophilic clay filler under continuous and slow stirring; g) ^: keep stirring until complete homogenization; and h) maintain rest with heating until the end of polymerization. 2. Process, according to claim 1, characterized by the fact that in step there the reactor is heated until it reaches a temperature between 120°C and 220°C, preferably 10 ^° C... 3. Process, according to claim 1, characterized by the fact that in step c) the catalyst belongs to the group of titanium alkoxides IV and is preferably tin octanoate. 4. Process, according to claim 1, characterized by the fact that in step d) the initiator belongs to the group of protic solvents and preferably be 1-dodecanol, 5. Process, according to claim 1, characterized by the fact that in step e) the reactor is kept under agitation in a variable range between 2700 rpm and 5000 rpm, preferably 3000 rpm. 6. Process, according to claim 1, characterized by the fact that in step f) the organic clay filler is added in a proportion of 1.0 to 12%, preferably 0.5% of the amount of L-Laethoxide monomer used in the synthesis. 7. process according to claim 6, characterized in that the organophilic clay is preferably organophyrized bentonite with 12-aminododecanoic acid _. ico, 3. Process, according to claim 1, characterized by the fact that in step g) stirring is maintained for 15 to 40 minutes. 9. Process, according to claim 1, characterized by the fact that in step h) the rest is maintained between 1 and 12 hours, preferably 1 hour.