Method For The Enzyme-Catalyzed Production Of Prepolymers For Producing Plastics

Abstract

A process for the enzyme-catalyzed preparation of prepolymers for the production of plastics, based on an enzyme-catalyzed polymerization of monomer or oligomer compounds in a single phase aqueous solution, as well as the separation of the prepolymers precipitated therefrom and their subsequent use for the production of plastics and plastic articles obtainable therefrom. In particular, the invention relates to respective methods for enzyme-catalyzed preparation of prepolymers with polyamide-type bonding structure for the production of polyamide-based plastics.

Claims

1. A process for preparing prepolymers for the production of plastics, wherein one or more monomer or oligomer compounds are subjected to a polycondensation reaction, which is characterized in that the prepolymer has a polyimide-type bonding structure and the polycondensation reaction is carried out in a single phase aqueous solution with the addition of one or more enzymes catalyzing the polymerization reaction.

2. The process of claim 1, wherein the prepolymers are precipitated from the single-phase aqueous reaction solution and then separated therefrom and further processed into plastics.

3. The process according to claim 1 for the preparation of prepolymers for the production of plastics which are selected from the group of thermoplastics and thermosetting plastics.

4. The process according to claim 1, wherein the prepolymer is polyimide.

5. The process according to claim 1, wherein the monomer and/or oligomer compounds are selected from the group comprising diamines, carboxylic acids, in particular hydroxycarboxylic acids, di- and tricarboxylic acids, amino carboxylic acids, caprolactams, particularly aminocaprolactams, and derivatives and mixtures thereof, respectively.

6. The process according to claim 1, wherein the enzymes are selected from the group of hydrolases, oxidoreductases and lyases, preferably from the group of hydrolases.

7. The process according to claim 1, wherein (i) the prepolymer has a polyimide-type bonding structure and (ii) as monomers or oligomers a mixture of one or more diamine compounds with one or more dicarboxylic acid compounds, one or more amino carboxylic acids or esters thereof, or caprolactam, in particular aminocaprolactam, and (iii) as enzyme a hydrolase, preferably a polyamidase or (amino)caprolactamase is used.

8. The process according to claim 1, wherein the monomer or oligomer compounds are prepared by fermentation, preferably by fermentation using a recombinant microorganism.

9. The process according to claim 1, comprising the steps a) preparing one or more monomer or oligomer compounds, preferably by fermentation or enzymatic reaction, b) separating the aqueous supernatants with the monomer or oligomer compounds dissolved therein, c) adding one or more enzymes catalyzing the polymerization reaction of the monomer or oligomer compounds to the aqueous solution containing one or more monomer or oligomer compounds, d) precipitating the prepolymers from the aqueous reaction solution, e) separating the precipitated prepolymers, preferably by centrifugation or filtration, f) optionally further processing of the separated prepolymers to plastics, and g) optionally further processing of the resulting plastics into plastic articles, preferably in spinning processes or thermoplastic or thermosetting molding processes, in particular in injection molding, casting or extrusion processes.

10. Use of the prepolymers obtainable by the process according claim 1 for the production of plastics, as well as plastic articles obtainable therefrom, in particular textiles, thermoplastic molded articles, packaging materials and building materials.

11. The process according to claim 2 for the preparation of prepolymers for the production of plastics which are selected from the group of thermoplastics and thermosetting plastics.

12. The process according to claim 2, wherein the prepolymer is polyamide.

13. The process according to claim 2, wherein the monomer and/or oligomer compounds are selected from the group comprising diamines, carboxylic acids, in particular hydroxycarboxylic acids, di- and tricarboxylic acids, amino carboxylic acids, caprolactams, particularly aminocaprolactams, and derivatives and mixtures thereof, respectively.

14. The process according to claim 2, wherein the enzymes are selected from the group of hydrolases, oxidoreductases and lyases, preferably from the group of hydrolases.

15. The process according to claim 2, wherein (i) the prepolymer has a polyamide-type bonding structure and (ii) as monomers or oligomers a mixture of one or more diamine compounds with one or more dicarboxylic acid compounds, one or more amino carboxylic acids or esters thereof, or caprolactam, in particular aminocaprolactam, and (iii) as enzyme a hydrolase, preferably a polyamidase or (amino)caprolactamase is used.

16. The process according to claim 2, wherein the monomer or oligomer compounds are prepared by fermentation, preferably by fermentation using a recombinant microorganism.

17. The process according to claim 2, comprising the steps a) preparing one or more monomer or oligomer compounds, preferably by fermentation or enzymatic reaction, b) separating the aqueous supernatants with the monomer or oligomer compounds dissolved therein, c) adding one or more enzymes catalyzing the polymerization reaction of the monomer or oligomer compounds to the aqueous solution containing one or more monomer or oligomer compounds, d) precipitating the prepolymers from the aqueous reaction solution, e) separating the precipitated prepolymers, preferably by centrifugation or filtration, f) optionally further processing of the separated prepolymers to plastics, and g) optionally further processing of the resulting plastics into plastic articles, preferably in spinning processes or thermoplastic or thermosetting molding processes, in particular in injection molding, casting or extrusion processes.

18. The process according to claim 3, wherein the enzymes are selected from the group of hydrolases, oxidoreductases and lyases, preferably from the group of hydrolases.

19. The process according to claim 3, wherein (i) the prepolymer has a polyamide-type bonding structure and (ii) as monomers or oligomers a mixture of one or more diamine compounds with one or more dicarboxylic acid compounds, one or more amino carboxylic acids or esters thereof, or caprolactam, in particular aminocaprolactam, and (iii) as enzyme a hydrolase, preferably a polyamidase or (amino)caprolactamase is used.

20. The process according to claim 3, wherein the monomer or oligomer compounds are prepared by fermentation, preferably by fermentation using a recombinant microorganism.

Description

EXAMPLES

[0122] In the following the invention is further illustrated by way of example. For the skilled person it is apparent that this example is exemplary only and will not narrow the scope of the invention.

[0123] For the synthesis of polymerization products based on dicarboxylic acids and diamines hydrolases from the EC-group 3 were used. The commercially available protease “subtilisin A” from Bacillus licheniformis A (company Megazyme; Order-No.: E-BSPRT) was used. The enzyme stock solution was 300 U/ml. The pH optimum of this enzyme lies at pH 7 -7.5, the pH stability lies at pH 5.5 -10.0 and the temperature optimum lies at 60° C.

[0124] Unless stated otherwise, all solutions used were applied in double-distilled water (ddH.sub.2O). As dicarboxylic acid 2,6-hexanedioic acid and 1,10-decanedioic acid were used. A 1M solution of 1,6-hexanedioic acid was prepared at 60° C. 1,10-decanedioic acid was either dissolved as a 200 mM solution in 99.8% ethanol or prepared as a 2.5 mM solution in water. As diamines 1,4-diaminobutane and 1,5-diaminopentane were used. Of each a 400 mM solution in water was prepared.

[0125] The enzymatic synthesis was carried out under shaking in test tubes with screw cap at 60° C. and 1500 rpm for 50-60 h in a preheated thermal shaker (“Thermo Shaker Incubator” MS-100). Therefore 100 μl enzyme solution were added to 1000 μl of the 1,4-diaminobutane and 62.2 μl of the 200 mM decanedioic acid (in ethanol). In order to achieve the total volume of 2.1 ml, 969 μl ddH.sub.2O was added.

[0126] Alternatively, 1000 μl 1,4-diaminobutane or 1,5-diaminopentane and 100 μl enzyme was were to 1000 μl of the 2.5 mM decanedioic acid solution and filled with ddH.sub.2O. Similarly, Likewise, 500 μl 1,6-hexanedioic acid solution and 100 μl enzyme were added to 1000 μl 1,5-diaminopentane or 1,4-diaminobutane and filled with ddH.sub.2O.

[0127] The initial pH value in the reaction was pH 5.5 in the case of hexanedioic acid and pH 10.0 in the case of decanedioic acid.

[0128] For the subsequent analysis, the synthesized samples were evaporated on a rotary evaporator under reduced pressure at 50 mbar at 60° C. From the evaporated synthesis batches 5-8 mg were weighed in each case and in about 1.5 ml HFIP solution (99.9% hexafluoroisopropanol, 0.1 wt % potassium trifluoroacetate) redissolved by stirring for several hours and then filtered (PTFE membrane 0.2 μm). The molecular weight (Mn and MW) and the dispersity of the synthesized products were determined by HFIP gel permeation chromatography (GPC HFIP). Depending on the synthesis batch both, prepolymers with smaller masses of about 700 -1300 Daltons as well as large polymers with masses between 100,000 and 300,000 Daltons were obtained; the dispersity was in each case below 1.25.

[0129] For further analysis, the evaporated synthesis batches were redissolved in about 200 μl HFIP solution and precipitated in an excess of cold methanol. Formed products precipitated; the supernatant containing the reactants was discarded. The samples were dried and re-examined using HFIP-GPC as well as IR spectroscopy, wherein in particular the short chain lengths of the prepolymers of 700-1300 Daltons were confirmed.