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CN-122011706-A - Biodegradable composite material for packaging and preparation method thereof

CN122011706ACN 122011706 ACN122011706 ACN 122011706ACN-122011706-A

Abstract

The invention belongs to the technical field of films, and particularly relates to a biodegradable composite material for packaging and a preparation method thereof. The biodegradable composite material for packaging comprises, by weight, 50-60 parts of polybutylene terephthalate-adipate, 40-50 parts of polylactic acid, 1-3 parts of filler, 0.5-1.5 parts of modified cellulose nano whisker, 0.1-0.5 part of chain extender and 1-3 parts of compatilizer. The biodegradable composite material for packaging has excellent barrier property, mechanical property, antibacterial property and ageing resistance.

Inventors

  • CHEN QING
  • WU JIWEI
  • ZHU JUNFENG
  • YU WEI

Assignees

  • 上海睿途新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (8)

  1. 1. The biodegradable composite material for package is characterized by comprising, by weight, 50-60 parts of polybutylene terephthalate-adipate, 40-50 parts of polylactic acid, 1-3 parts of filler, 0.5-1.5 parts of modified cellulose nano whisker, 0.1-0.5 part of chain extender and 1-3 parts of compatilizer; The preparation process of the modified cellulose nano whisker comprises the following steps: (1) Adding sodium periodate into the cellulose nano whisker dispersion liquid under the light-shielding condition, adjusting the pH value, and purifying after the reaction to obtain the aldehyde group cellulose nano whisker; (2) Adding the aldehyde cellulose nano whisker into deionized water, adding beta-alanyl-L-histidine, reacting, and purifying to obtain the modified cellulose nano whisker.
  2. 2. The composite material for biodegradable packaging according to claim 1, wherein the mass ratio of the sodium periodate and the cellulose nanowhisker dispersion in the step (1) is 1 (8-10), the concentration of the cellulose nanowhisker dispersion is 0.1-0.2wt%, the reaction temperature is 40-60 ℃ for 3-5 hours, and the pH is adjusted to 3-4.
  3. 3. The composite material for biodegradable packaging according to claim 1, wherein in the step (2), the mass ratio of the beta-alanyl-L-histidine to the formylated cellulose nanowhisker is 1 (1-5), the reaction temperature is 40-45 ℃ and the reaction time is 5-8h.
  4. 4. The composite material for biodegradable packaging according to claim 1, characterized in that said filler is prepared by the following process: Adding talcum powder into zinc chloride solution, adding sodium hydroxide, stirring, filtering, washing and drying to obtain the filler.
  5. 5. The composite material for biodegradable packaging according to claim 4, wherein the ratio of the talcum powder, sodium hydroxide and zinc chloride solution is 1g (0.2-0.4) g (10-15) mL, the concentration of the zinc chloride solution is 0.1-0.2mol/L, and the stirring time is 2-3h.
  6. 6. The composite material for biodegradable packaging according to claim 1, wherein the chain extender is SG-20 chain extender and the compatibilizer is maleic anhydride grafted polylactic acid.
  7. 7. A method of preparing the composite material for biodegradable packaging according to any one of claims 1 to 6, comprising the steps of: s1, uniformly mixing polybutylene terephthalate-adipic acid, polylactic acid and a compatilizer according to the weight parts to prepare a premix A; s2, uniformly mixing the filler and the modified cellulose nano whisker to prepare a premix B; S3, premixing the premix A and the chain extender, then blending with the premix B, and performing extrusion granulation, cooling bracing, air drying, granulating and film blowing.
  8. 8. The method for producing a composite material for biodegradable packaging according to claim 7, wherein the extrusion temperature in step S3 is 150-175 ℃, the film blowing temperature is 155-165 ℃, the rotational speed is 30-50rpm, the inflation ratio is 2-5 times, and the stretch ratio is 2-5 times.

Description

Biodegradable composite material for packaging and preparation method thereof Technical Field The invention belongs to the technical field of films, and particularly relates to a biodegradable composite material for packaging and a preparation method thereof. Background The cigarette packaging film is used as an important outer packaging material of a cigarette product, and has good mechanical properties to ensure the integrity and breakage resistance of the package, and excellent barrier property and sealing property to prevent the product in the package from being invaded by external environment factors such as moisture, oxygen, microorganisms and the like, and effectively block the loss of the fragrance of the cigarette, and keep the taste and quality of the cigarette. At present, the cigarette packaging film widely applied in the market is mainly a biaxially oriented polypropylene film, and the film has good mechanical strength and barrier property, but is derived from petroleum-based materials and is difficult to degrade in natural environment. Polylactic acid is used as a biodegradable material derived from renewable plant resources, has good biocompatibility and processability, and has wide application prospect in the field of packaging materials. However, polylactic acid has poor barrier property, high water vapor and oxygen transmittance, and difficulty in effectively preventing volatilization of cigarette flavor and invasion of external moisture, and can not meet the requirement of cigarette package on high barrier property when used alone. Polybutylene terephthalate-adipate is another biodegradable material with excellent properties, good flexibility and toughness, but its mechanical strength is relatively low and its barrier ability to water vapor and oxygen is limited. The polylactic acid and the polybutylene terephthalate-adipate are blended, which can complement the performance deficiency of the two to a certain extent, but the direct blending has the problems of poor compatibility, weak interfacial binding force and the like due to the large polarity difference of the two, so that the comprehensive performance of the blended material is difficult to reach an ideal state. In addition, cigarettes are easy to be polluted by microorganisms in the storage and transportation processes, and common packaging films lack antibacterial functions and cannot effectively inhibit microorganism breeding, so that the sanitary safety and shelf life of products are affected. Therefore, how to develop a cigarette packaging film material with excellent comprehensive performance on the premise of keeping the biodegradability of the material and improving the mechanical property, the barrier property and the antibacterial property of the material at the same time has become a technical problem to be solved in the field. Disclosure of Invention In order to overcome the defects of the prior art, the first aim of the invention is to provide a composite material for biodegradable packaging, which has excellent barrier property, mechanical property, antibacterial property and ageing resistance. The second aim of the invention is to provide a preparation method of the composite material for biodegradable packaging, which is simple to operate. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The biodegradable composite material for package includes the materials including polybutylene terephthalate-adipic acid 50-60 weight portions, polylactic acid 40-50 weight portions, stuffing 1-3 weight portions, modified cellulose nanometer whisker 0.5-1.5 weight portions, chain extender 0.1-0.5 weight portions and compatilizer 1-3 weight portions; The preparation process of the modified cellulose nano whisker comprises the following steps: (1) Adding sodium periodate into the cellulose nano whisker dispersion liquid under the light-shielding condition, adjusting the pH value, and purifying after the reaction to obtain the aldehyde group cellulose nano whisker; (2) Adding the aldehyde cellulose nano whisker into deionized water, adding beta-alanyl-L-histidine, reacting, and purifying to obtain the modified cellulose nano whisker. Further, in the step (1), the mass ratio of the sodium periodate to the cellulose nano whisker dispersion liquid is 1 (8-10), the concentration of the cellulose nano whisker dispersion liquid is 0.1-0.2wt%, the reaction temperature is 40-60 ℃ for 3-5h, and the pH is adjusted to 3-4. Further, in the step (2), the mass ratio of the beta-alanyl-L-histidine to the aldehyde cellulose nano whisker is 1 (1-5), the reaction temperature is 40-45 ℃ and the reaction time is 5-8h. Further, the preparation process of the filler is as follows: Adding talcum powder into zinc chloride solution, adding sodium hydroxide, stirring, filtering, washing and drying to obtain the filler. Further, the dosage ratio of the talcum powder to the sodium hydroxide to the zinc chloride so