CN116284659A - A high-strength lactic acid-based biodegradable elastomer material - Google Patents

Abstract

The application discloses a high-strength lactic acid-based biodegradable elastomer material. In this technical scheme, using lactic acid, caprolactone, branching agent, and end group modifier as raw materials, the end group active branched prepolymer is prepared by melting polycondensation method, and the isocyanate is reacted with the end group active branched prepolymer. High strength lactic acid based biodegradable elastomer material. The lactic acid-based elastomer can be cross-linked and cured at 50-100°C, and the cured elastomer has excellent tensile strength and biodegradability. By adjusting the type and amount of branching agent, end group modifier and isocyanate, and introducing different topological structures, the molecular structure of the elastomer and the force between molecular chains can be adjusted, thereby changing the product performance and achieving high strength of the elastomer. and biodegradability.

Description

A high-strength lactic acid-based biodegradable elastomer material

technical field

The present application relates to the technical field of biodegradable materials, in particular to a high-strength lactic acid-based biodegradable elastomer material.

Background technique

Among various polymers, elastomers are cross-linked and amorphous polymers known for their high elongation at break, high resistance to stress without permanent deformation. Due to the high elasticity of elastomer, it is widely used in electronics industry, automobile industry and our daily life, however, except for natural rubber, there are few bio-based elastomers for engineering applications. Therefore, the design and synthesis of bio-based elastomers as next-generation elastomers are of great importance and urgent need in both academia and industry. Carbohydrate derivatives, as the most abundant biomass feedstock, are used as monomers for the synthesis of bio-based polymers. Among them, lactic acid (2-hydroxypropionic acid, LA) is ubiquitous in nature and produced by bacterial fermentation of carbohydrates. LA has been identified by the US Department of Energy as one of the "big 12" potential biomass-based compounds.

Bio-based elastomers are wholly or partly derived from renewable resources and are a new type of polymer biomaterials, mainly used in soft tissue engineering and drug delivery. The synthetic degradable bioelastomer has a three-dimensional crosslinked network structure similar to natural elastomers, high flexibility and elasticity. Chinese invention patent CN201410573539.6 discloses a polyester elastomer and its preparation method. The elastomer has good resilience and biodegradability, but the tensile strength of the elastomer can only reach a maximum of 6.75MPa. Chinese invention patent CN201810179219.0 discloses a biodegradable thermoplastic elastomer material and its preparation method. The biodegradable thermoplastic elastomer material has good elasticity and good degradation performance, but its tensile strength can only reach about 10MPa. It is also reported (Polym.Chem.6 (2015) 8112–8123) that a biocompatible polylactic acid/butylene glycol/sebacic acid/coating acid ester copolyester elastomer was synthesized by direct melt polycondensation. The elastomer exhibits excellent elongation at break (400-1600%), but its highest tensile strength is only 4.9MPa.

The biodegradable elastomers prepared in the prior art often cannot balance the high strength and high elasticity of the elastomers.

Contents of the invention

In view of this, the present application provides a high-strength lactic acid-based biodegradable elastomer material, which can take into account the high strength and high elasticity of the elastomer.

It has been generally recognized that, in the related art, the prepared biodegradable elastomers often cannot balance the high strength and high elasticity of the elastomer.

Based on this problem, the inventors simultaneously introduced topological structure and dynamic hydrogen bonding into lactic acid-based biodegradable elastomers, using branching agent, end group modifier, caprolactone and lactic acid as raw materials, and adopted a one-step melt polycondensation method Preparation of end group living branched prepolymer, the branched prepolymer topology structure and end group type are adjustable, molecular weight controllable; reacting isocyanate with end group living branched prepolymer to prepare high-strength lactic acid-based biodegradable elastic body material. The molecular structure and material properties of the lactic acid-based elastomer can be adjusted by adjusting the type and amount of each raw material.

Based on this, the present invention is created.

This application provides a high-strength lactic acid-based biodegradable elastomer material, which is prepared by polymerization of the following components by weight:

Suitably but not limitatively, the end-group living branched prepolymer is prepared by melt polycondensation method from the following components by weight:

Suitably but without limitation, the isocyanate is toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexaethylene diisocyanate One or more of methyl diisocyanate (HDI), lysine diisocyanate (LDI) and various oligomers thereof.

Suitably but not limitatively, the diluent is 1,4-dioxane, tetrahydrofuran (THF), N,N-dimethylformamide, N,N-dimethylacetamide, toluene, xylene , one or any of several diphenyl ethers.

Suitably but without limitation, the branching agent is citric acid, glycerol, pentaerythritol, boric acid, trimethylolpropane, trimethylolethane, 2,2-bis(hydroxymethyl)propionic acid, One or more of 2,2-bis(hydroxymethyl)butyric acid, 1,2,3,4-butanetetracarboxylic acid, dipentaerythritol, xylitol, and sorbitol.

Suitable but not limited, the end group modifier and the chain extender are ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl One or more of glycol, oxalic acid, adipic acid, ethylenediamine, propylenediamine, hexamethylenediamine, p-phenylenediamine, polyetheramine.

Suitable but not limiting, the catalyst A is one or more of SnCl ₂ , Sn(Oct) ₂ , Sn powder, dibutyltin dilaurate, Zn powder, and ZnO.

Suitable but non-limiting, the catalyst B is one or more of tetrabutyl titanate, 4-dimethylaminopyridine, p-toluenesulfonic acid, phosphomolybdic acid, concentrated sulfuric acid, and concentrated phosphoric acid.

The preparation process of the above-mentioned high-strength lactic acid-based biodegradable elastomer material is as follows: add 100 parts of end-group active branched prepolymers into the reactor, raise the temperature to 120°C, and stir mechanically for 1 hour to remove the system moisture in. Then lower the temperature to 40-80°C, add 30-90 parts of diluent into the reactor, in nitrogen atmosphere, gradually add 1-30 parts of isocyanate monomer, 0.2-2 parts of catalyst A within 0.5 hours, and mechanically stir for 4 hours . Then add 1-10 parts of chain extender into the reactor, and continue mechanical stirring for 12h. Finally, pour the reactant into a polytetrafluoroethylene mold to evaporate the solvent at room temperature for 24 hours, and then evaporate the solvent in a vacuum oven at 80°C for 24 hours to obtain a high-strength lactic acid-based biodegradable elastomer material.

Compared with related technologies, the present application has the following beneficial effects:

The high-strength lactic acid-based biodegradable elastomer material involved in this application realizes the high strength and high elasticity of lactic acid-based elastomers by introducing branched structures and hydrogen bond forces into the molecular structure of the elastomer. It is a very environmentally friendly and efficient preparation A new approach to biodegradable elastomers. Firstly, using branching agent, end group modifier, caprolactone and lactic acid as raw materials, the end group living branched prepolymer is prepared by one-step melt polycondensation method. The branched prepolymer topology and end group type can be adjusted. The molecular weight is controllable; and then the isocyanate is reacted with the terminal active branched prepolymer to prepare a high-strength lactic acid-based biodegradable elastomer material. The molecular structure and material properties of polyurethane elastomers can be adjusted by adjusting the types and amounts of branching agents, end group modifiers and isocyanates.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

In the description of the present application, it should be understood that the terms "first" and "second" are used for description purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected, or electrically connected, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction of two components relation. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

The following disclosure provides many different implementations or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and arrangements of specific examples are described below. Of course, they are examples only and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or reference letters in various instances, such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, various specific process and material examples are provided herein, but one of ordinary skill in the art may recognize the use of other processes and/or the use of other materials.

Example 1:

(1) 100 parts of lactic acid monomer, 20 parts of caprolactone monomer and 10 parts of citric acid were vacuumed at 120°C to control the pressure of the reaction system at 70kPa, polymerized for 4 hours, and the moisture generated during the reaction was removed to obtain a branched precursor Polymer; then add 10 parts of 1,4-butanediol and 0.5 parts of tetrabutyl titanate, raise the temperature to 160°C, vacuum control the pressure of the reaction system at 50kPa, and react for 2 hours to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated active branched prepolymer to 120°C, and stir mechanically for 1 hour to remove moisture in the system; then cool down to 50°C, add 30 parts of THF to the reactor, and , 20 parts of isophorone diisocyanate and 0.5 parts of dibutyltin dilaurate were gradually added within 0.5 hours, and mechanically stirred for 4 hours; then 10 parts of p-phenylenediamine were added to the reactor, and mechanical stirring was continued for 12 hours. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

Example 2:

(increased caprolactone)

(1) 100 parts of lactic acid monomer, 40 parts of caprolactone monomer and 10 parts of citric acid were vacuumed at 120°C to control the pressure of the reaction system at 70kPa, polymerized for 4 hours, and the moisture generated during the reaction was removed to obtain a branched precursor polymer; then add 10 parts of 1,4-butanediol and 0.3 parts of tetrabutyl titanate, raise the temperature to 160°C, vacuumize the reaction system to control the pressure at 50kPa, and react for 4 hours to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated reactive branched prepolymer to 120°C and stir mechanically for 1 hour to remove moisture from the system; then cool down to 50°C and mix 50 parts of 1,4-dioxane+THF ( Part ratio 1.4-dioxane:THF=2:1) into the reactor, in nitrogen atmosphere, gradually add 20 parts of isophorone diisocyanate, 0.5 parts of Sn(Oct) ₂ within 0.5h, mechanically Stir for 4h; then add 10 parts of p-phenylenediamine to the reactor and continue mechanical stirring for 12h. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

Example 3:

(change branching agent)

(1) Put 100 parts of lactic acid monomer, 20 parts of caprolactone monomer and 10 parts of pentaerythritol in a vacuum at 120°C to control the pressure of the reaction system at 70kPa, polymerize for 4 hours, and remove the moisture generated during the reaction to obtain branched prepolymerization Then add 10 parts of adipic acid and 0.5 parts of p-toluenesulfonic acid + tetrabutyl titanate (ratio of p-toluenesulfonic acid: tetrabutyl titanate = 1:1) composite catalyst, heat up to 160 ° C, pump The pressure of the reaction system was controlled at 50 kPa by vacuum, and the reaction was carried out for 2 hours to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated active branched prepolymer to 120°C and stir mechanically for 1 hour to remove moisture from the system; then cool down to 50°C and add 30 parts of 1,4-dioxane to the reaction In the reactor, in a nitrogen atmosphere, gradually add 20 parts of isophorone diisocyanate and 0.8 parts of dibutyltin dilaurate within 0.5 hours, and mechanically stir for 4 hours; then add 10 parts of p-phenylenediamine into the reactor and continue to mechanically stir 12h. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

Example 4:

(change isocyanate and second step end group modifier)

100 parts of lactic acid monomer, 20 parts of caprolactone monomer and 10 parts of pentaerythritol were evacuated at 120°C to control the pressure of the reaction system at 70kPa, and polymerized for 4 hours to remove the moisture generated during the reaction to obtain a branched prepolymer; then Add 10 parts of adipic acid and 0.2 parts of p-toluenesulfonic acid + tetrabutyl titanate (the ratio of parts to p-toluenesulfonic acid: tetrabutyl titanate = 1:1) composite catalyst, raise the temperature to 160°C, and vacuumize to control the reaction The system pressure was 50kPa, and the reaction was carried out for 2 hours to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated active branched prepolymer to 120°C and stir mechanically for 1 hour to remove moisture from the system; then cool down to 50°C and add 70 parts of 1,4-dioxane to the reaction In the reactor, in a nitrogen atmosphere, gradually add 20 parts of toluene diisocyanate and 0.5 parts of dibutyltin dilaurate within 0.5 hours, and mechanically stir for 4 hours; then add 10 parts of ethylenediamine into the reactor, and continue to mechanically stir for 12 hours. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

Example 5:

(change isocyanate and second step end group modifier)

(1) 100 parts of lactic acid monomer, 20 parts of caprolactone monomer and 10 parts of citric acid were vacuumed at 120°C to control the pressure of the reaction system at 70kPa, polymerized for 4 hours, and the moisture generated during the reaction was removed to obtain a branched precursor polymer; then add 10 parts of 1,4-butanediol and 0.5 parts of p-toluenesulfonic acid+tetrabutyl titanate (parts ratio p-toluenesulfonic acid: tetrabutyl titanate = 1:1) composite catalyst, and heat up to 160° C., vacuuming to control the pressure of the reaction system at 50 kPa, and reacting for 2 hours to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated reactive branched prepolymer to 120°C, and stir mechanically for 1 hour to remove moisture in the system; then cool down to 50°C, add 50 parts of THF to the reactor, and , Gradually add 20 parts of dicyclohexylmethane diisocyanate and 0.5 parts of dibutyltin dilaurate within 0.5 hours, and mechanically stir for 4 hours; then add 10 parts of ethylenediamine into the reactor, and continue to mechanically stir for 12 hours. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

Embodiment 6:

(increase branching agent)

(1) 100 parts of lactic acid monomer, 20 parts of caprolactone monomer and 20 parts of citric acid were vacuumed at 120°C to control the pressure of the reaction system at 70kPa, polymerized for 4 hours, and the moisture generated during the reaction was removed to obtain a branched precursor polymer; then add 20 parts of 1,4-butanediol and 0.5 parts of tetrabutyl titanate catalyst, raise the temperature to 160°C, vacuumize and control the pressure of the reaction system at 50kPa, and react for 1h to obtain a hydroxyl-terminated branched prepolymer.

(2) Warm up 100 parts of hydroxyl-terminated reactive branched prepolymer to 120°C, and stir mechanically for 1 hour to remove moisture in the system; then cool down to 50°C, add 30 parts of 1,4-dioxane+THF ( Part ratio 1.4-dioxane:THF=2:1) into the reactor, in nitrogen atmosphere, gradually add 30 parts of dicyclohexylmethane diisocyanate, 0.5 parts of dibutyltin dilaurate within 0.5h, mechanically Stir for 4h; then add 20 parts of ethylenediamine to the reactor and continue mechanical stirring for 12h. The reactant was poured into a polytetrafluoroethylene mold at room temperature to evaporate the solvent for 24 hours, and then molded and solidified at 80°C for 24 hours under vacuum conditions to obtain a high-strength lactic acid-based biodegradable elastomer material.

The mechanical property of each embodiment elastomer of table 1

serial number Tensile strength/MPa Elongation at break/% Toughness/MJ·m ^-3 Example 1 23.32 401 37.98 Example 2 18.27 323 25.23 Example 3 38.76 276 63.26 Example 4 35.18 356 48.64 Example 5 28.73 443 40.15 Example 6 37.52 204 55.61

The above is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person familiar with the technical field can easily conceive of changes or changes within the technical scope disclosed in this application Replacement should be covered within the protection scope of this application.

Claims (8)

1. A high-strength lactic acid-based biodegradable elastomer material, characterized in that it is prepared by polymerization of the following components by weight:

2. The high-strength lactic acid-based biodegradable elastomer material according to claim 1, wherein the end-group active branched prepolymer is prepared by melt polycondensation from the following components by weight:

3. The high-strength lactic acid-based biodegradable elastomer material according to claim 1, wherein the isocyanate is toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI) and one or more of various oligomers thereof. 4. The high-strength lactic acid-based biodegradable elastomer material according to claim 1, wherein the diluent is 1,4-dioxane, tetrahydrofuran (THF), N,N-dimethylformaldehyde One or more of amides, N,N-dimethylacetamide, toluene, xylene, and biphenyl ether. 5. The high-strength lactic acid-based biodegradable elastomer material according to claim 1, wherein the branching agent is citric acid, glycerol, pentaerythritol, boric acid, trimethylolpropane, trimethylol Ethane, 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butyric acid, 1,2,3,4-butane tetracarboxylic acid, dipentaerythritol, xylitol, One or any combination of sorbitol. 6. according to the described high-strength lactic acid-based biodegradable elastomer material of claim 2, it is characterized in that, described terminal modifier, described chain extender are ethylene glycol, 1,2-propanediol, 1, One of 4-butanediol, 1,6-hexanediol, neopentyl glycol, oxalic acid, adipic acid, ethylenediamine, propylenediamine, hexamethylenediamine, p-phenylenediamine, polyetheramine species or any number of species. 7. The high-strength lactic acid-based biodegradable elastomer material according to claim 1, wherein the catalyst A is SnCl ₂ , Sn(Oct) ₂ , Sn powder, dibutyltin dilaurate, Zn powder, ZnO one or any of several. 8. The high-strength lactic acid-based biodegradable elastomer material according to claim 2, wherein the catalyst B is tetrabutyl titanate, 4-dimethylaminopyridine, p-toluenesulfonic acid, phosphomolybdic acid, One or more of concentrated sulfuric acid and concentrated phosphoric acid.