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CN-121975286-A - Biodegradable PHA/PCL composite material and preparation method thereof

CN121975286ACN 121975286 ACN121975286 ACN 121975286ACN-121975286-A

Abstract

The invention discloses a biodegradable PHA/PCL composite material and a preparation method thereof, which belong to the technical field of polymer compounding, wherein nano cellulose crystal is modified by quaternary ammonium salt and then is subjected to inverse emulsification method and chemical crosslinking with chitosan to obtain chitosan/nano cellulose crystal microspheres, then coordination self-assembly of tannic acid and zinc ions is utilized to prepare tannic acid zinc composite powder, and finally PHA, PCL, chitosan/nano cellulose crystal microspheres and tannic acid zinc composite powder are jointly dissolved in 1, 2-dichloroethane, toluene-2, 4-diisocyanate, glycerol and butyl tin dilaurate are added, and the PHA/PCL composite material is obtained through casting and curing, so that the PHA/PCL composite material has excellent mechanical property, antibacterial property, oxidation resistance and water resistance stability while full-component biodegradability is realized.

Inventors

  • JU SHAOJUN

Assignees

  • 阜南县顺昌塑业有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. A method for preparing biodegradable PHA/PCL composite material, which is characterized by comprising the following steps: The method comprises the steps of modifying nano cellulose crystal by quaternary ammonium salt, and then carrying out inverse emulsification and chemical crosslinking on the modified nano cellulose crystal and chitosan to obtain chitosan/nano cellulose crystal microspheres; and step two, dissolving PHA, PCL, chitosan/nanocellulose crystal microspheres and zinc tannate composite powder in 1, 2-dichloroethane, adding toluene-2, 4-diisocyanate, glycerol and butyltin dilaurate, and casting and curing to obtain the PHA/PCL composite material.
  2. 2. The preparation method of the biodegradable PHA/PCL composite material according to claim 1, wherein the specific preparation steps of the chitosan/nanocellulose crystal microsphere are as follows: Adding chitosan powder and quaternary ammonium salt modified nano cellulose crystal into 2wt% acetic acid aqueous solution, and performing ultrasonic dispersion to prepare a chitosan/nano cellulose crystal mixed solution which is used as a water phase; Stirring petroleum ether, span 80 and Tween 60 at 40-50 ℃ and 600-700rpm for 30-50min to obtain an oil phase, adding a chitosan/nanocellulose crystal mixed solution, continuously stirring for 1-2h, adding terephthalaldehyde at 50-60 ℃ and stirring for 1-2h, dropwise adding ammonia water to adjust the pH value to 9-10, centrifuging, collecting solids, washing the supernatant with deionized water and ethanol alternately to be neutral, and freeze-drying to constant weight to obtain chitosan/nanocellulose crystal microspheres.
  3. 3. The preparation method of the biodegradable PHA/PCL composite material according to claim 2, wherein the dosage ratio of the chitosan powder to the quaternary ammonium salt modified nanocellulose crystal to the 2wt% acetic acid aqueous solution is 8-10g to 3.2-4.6g to 400-500mL, and the dosage ratio of the petroleum ether to span 80 to tween 60 to the chitosan/nanocellulose crystal mixed solution to the terephthalaldehyde is 1000-1200mL to 57.6-64.9g to 2.4-3.6g to 200-300mL to 10-12g.
  4. 4. The preparation method of the biodegradable PHA/PCL composite material according to claim 2, wherein the specific preparation steps of the quaternary ammonium salt modified nanocellulose crystal are as follows: adding the nanocellulose crystal into distilled water, carrying out ultrasonic grinding for 15-25min to obtain nanocellulose crystal suspension, regulating the pH value to 10 by using sodium hydroxide solution, adding 65wt% of 2, 3-epoxypropyl trimethyl ammonium chloride solution, stirring for 3.5-4.5h at 60-70 ℃, stirring for 15-20h at room temperature, transferring into a dialysis bag, dialyzing in distilled water for 7-10 days, and freeze-drying to constant weight to obtain the quaternary ammonium salt modified nanocellulose crystal.
  5. 5. The method for preparing biodegradable PHA/PCL composite material according to claim 4, wherein the dosage ratio of the nanocellulose crystal, distilled water and 65wt% 2, 3-epoxypropyl trimethyl ammonium chloride solution is 4-6g:400-700mL:7.6-8.2mL.
  6. 6. The method for preparing biodegradable PHA/PCL composite material according to claim 1, wherein the zinc tannate composite powder is prepared by the steps of: Dissolving tannic acid in deionized water, slowly adding 1mol/L zinc sulfate aqueous solution under stirring, regulating the pH value to 5-5.5 with sodium hydroxide solution, stirring for 2-3h, centrifuging, washing the precipitate with deionized water for 3-5 times, and freeze-drying to constant weight to obtain zinc tannate composite powder.
  7. 7. The method for preparing biodegradable PHA/PCL composite material according to claim 6, wherein the dosage ratio of tannic acid, deionized water and 1mol/L zinc sulfate aqueous solution is 6-8 g/60-90 mL/12-15 mL.
  8. 8. The method for preparing the biodegradable PHA/PCL composite material according to claim 1, wherein the PHA/PCL composite material is prepared by the following specific steps: mixing PHA and PCL uniformly to obtain mixed resin, dissolving the mixed resin in 1, 2-dichloroethane, sequentially adding chitosan/nano cellulose crystal microsphere, zinc tannate composite powder, toluene-2, 4-diisocyanate, glycerol and butyltin dilaurate, stirring for 4-6h at 70-80 ℃ under the protection of nitrogen, casting the reaction solution into a polytetrafluoroethylene mould, placing the mould in a vacuum drying oven, solidifying for 48-72h at 25-40 ℃ and 0.1-0.15MPa, and demoulding to obtain the PHA/PCL composite material.
  9. 9. The method for preparing biodegradable PHA/PCL composite material according to claim 8, wherein the dosage ratio of the mixed resin, 1, 2-dichloroethane, chitosan/nanocellulose crystal microsphere, zinc tannate composite powder, toluene-2, 4-diisocyanate, glycerol and butyltin dilaurate is 100g:250-350mL:8-10g:3-5g:14.5-16.5g:3.3-4.6g:0.5-0.8g; the PHA content in the mixed resin is 20-40wt%.
  10. 10. Biodegradable PHA/PCL composite material prepared by the preparation method of the biodegradable PHA/PCL composite material according to any one of claims 1-9.

Description

Biodegradable PHA/PCL composite material and preparation method thereof Technical Field The invention belongs to the technical field of polymer compounding, and particularly relates to a biodegradable PHA/PCL composite material and a preparation method thereof. Background The biodegradable polymer material is a research hotspot in the field of materials, and the PHA/PCL composite material is a novel polymer material compounded by two completely biodegradable aliphatic polyesters of Polyhydroxyalkanoate (PHA) and Polycaprolactone (PCL) through processes such as melt blending and the like, and is characterized in that the biodegradability of the two materials is maintained (the two materials can be decomposed into water and carbon dioxide in natural environment or organisms to return to nature), and meanwhile, the precise adaptation of key indexes such as mechanical property, degradation rate and the like can be realized through component proportion regulation and process optimization. The composite material is designed for solving the performance defect of a single degradable material, realizing 'advantage complementation and performance synergy' to expand application scenes, wherein a single PHA has short plates with high crystallinity, large brittleness, poor thermal stability and the like, a single PCL has the problems of weak biological activity, slow degradation rate, low mechanical strength and the like, the biological activity and the fast degradation rate of the PHA can be utilized for compensating the PCL defect by compounding the PHA, and meanwhile, the defect of the PHA is improved by virtue of the flexibility and the processability of the PCL, and the composite material has shown important application value in the fields of medical health, packaging, daily necessities, agricultural environmental protection and the like. The invention of China patent application with publication number CN110564122A discloses a degradable antibacterial film and a preparation method thereof, the proposal takes polycaprolactone and polyhydroxyalkanoate as main matrixes, adds the acetyl tributyl citrate as a green plasticizer and carboxymethyl chitosan as an antibacterial agent, and the films are prepared by extrusion granulation through a double screw extruder, flat vulcanization and hot press molding after mixing and stirring, thus the prepared film has good degradability and antibacterial property and is suitable for the fields of environmental protection packaging and the like. However, according to the scheme, hydrophilic carboxymethyl chitosan is directly added into a hydrophobic polymer matrix, the polarity difference of the hydrophilic carboxymethyl chitosan and the hydrophobic polymer matrix is large, the compatibility is poor, a large number of microscopic stress concentration points are introduced into the material, and when external force is applied, cracks are easy to initiate and expand from weak interfaces, so that the mechanical property of the material is reduced. Disclosure of Invention The invention aims to provide a biodegradable PHA/PCL composite material and a preparation method thereof, which solve the problems of weak bonding and reduced mechanical property of a filler and a matrix interface caused by directly adding a hydrophilic antibacterial agent in the above-mentioned comparison patent through chemical modification and structural design, firstly modify nano cellulose crystal by using quaternary ammonium salt, then dynamically and covalently crosslink with chitosan through reverse emulsification to obtain chitosan/nano cellulose crystal microspheres, then form chemical bonding with a chain extender and a crosslinking agent in the matrix in the subsequent polymerization as a reinforcing phase with multiple active points, and improve the water-resistant stability of interface bonding. In addition, the quaternary ammonium salt nanocellulose crystal and chitosan endow the material with antibacterial property, the zinc tannate provides antioxidant protection, the dynamic imine bond and coordination bond enhance the toughness of the material, the whole component is biodegradable, and the multifunctional integration of reinforcement, toughening, antibacterial and antioxidant is realized. The aim of the invention can be achieved by the following technical scheme: A method for preparing biodegradable PHA/PCL composite material, comprising the following steps: The preparation method comprises the steps of carrying out quaternary ammonium salt modification on the nano-cellulose crystal, carrying out inverse emulsification and chemical crosslinking on the nano-cellulose crystal and chitosan to obtain chitosan/nano-cellulose crystal microspheres, and preparing the zinc tannate composite powder through coordination self-assembly. And thirdly, dissolving PHA, PCL, chitosan/nanocellulose crystal microspheres and zinc tannate composite powder in 1, 2-dichloroethane, adding toluene-2, 4-diisocyanate, glycero