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CN-121991331-A - Preparation method and application of sulfur-containing naturally degradable high molecular weight polyester PES

CN121991331ACN 121991331 ACN121991331 ACN 121991331ACN-121991331-A

Abstract

The invention belongs to the technical field of naturally degradable materials, and relates to a preparation method and application of naturally degradable high molecular weight polyester. The series of natural degradable novel high molecular weight polyesters are synthesized by using two sulfur-containing organic dibasic acids and dihydroxyl compounds as raw materials by adopting a melt polymerization method, and can be used for preparing various packaging materials with high requirements on mechanical properties and degradation, such as food packaging, fast-food packaging and the like.

Inventors

  • CHENG ZHENGZAI
  • Yuan Shenao

Assignees

  • 武汉科技大学

Dates

Publication Date
20260508
Application Date
20241104

Claims (7)

  1. 1. A preparation method of sulfur-containing naturally degradable high molecular weight polyester PES is characterized in that the prepared sulfur-containing naturally degradable high molecular weight polyester PES has a molecular structure as follows: PES1: PES2: wherein m, r is a positive integer between 20 and 30, n, s is a positive integer between 30 and 50.
  2. 2. A preparation method of sulfur-containing naturally degradable high molecular weight polyester PES comprises the following two main steps: 1) Taking 2, 5-thiophene dicarboxylic acid, 4' -dithiobisbenzoic acid with CAS of 1155-51-7 and a dihydroxy compound as raw materials, stirring the three raw materials at 160-185 ℃ under the action of normal pressure and a catalyst for 4.0-5.0h to complete esterification, raising the temperature to 200-220 ℃ and continuing to react for 2.0-3.5h under the pressure environment of 5-15 KPa to obtain a polyester crude product; 2) Cooling the crude polyester product, adding a certain amount of chloroform, vibrating to promote dissolution, filtering, adding ethanol or propanol into the filtrate until the generated precipitate is not increased, washing the filtered filter residue with cold ethanol to remove impurities, and then vacuum drying at 40-60 ℃ for 1.0-2.0 h to obtain the required sulfur-containing naturally degradable high molecular weight polyester PES.
  3. 3. A process for preparing a sulfur-containing naturally degradable high molecular weight polyester PES as claimed in claim 2, wherein in the step 1) of claim 2, the dihydroxy compound is one of the following diols, diol 3a, having the structural formula Diol 3b of the formula
  4. 4. The process for preparing a sulfur-containing naturally degradable high molecular weight polyester PES according to claim 2, characterized in that the molar ratio of 2, 5-thiophenedicarboxylic acid, 4' -dithiobisbenzoic acid and dihydroxy compound is 1:1:1.5 to 1:1:2.5.
  5. 5. The method for preparing the sulfur-containing naturally degradable high molecular weight polyester PES according to claim 2, wherein the catalyst in claim 2 is tris (ethylenediamine) ruthenium chloride and 1, 2-diphenylethylenediamine ruthenium, and the catalyst is used in an amount of 0.01% -0.09% of the total substances of reactants.
  6. 6. The use of the sulfur-containing naturally degradable high molecular weight polyester PES prepared by the preparation method according to any one of claims 1-5 as a main raw material of a functional film is characterized in that the sulfur-containing naturally degradable high molecular weight polyester PES is fully banburying according to the following components by mass ratio, wherein the mass ratio of the sulfur-containing naturally degradable high molecular weight polyester PES to a toughening agent is 100: (3-4), and after banburying is finished, the polyester film material with the film thickness of 13-30 mu m is prepared by extrusion blow molding, extrusion casting and extrusion stretching, and has good mechanical properties compared with the prior polyester, and is used for various packaging and covering places with higher stretching requirements, such as food packaging, functional greenhouse film, fast-food packaging and the like, and the toughening agent is one of polyvinyl acetate, polyvinyl butyral and polyvinyl butyral.
  7. 7. The use of a polyester produced by the process for producing a sulfur-containing naturally degradable high molecular weight polyester PES as claimed in claim 6, wherein the produced polyester material has a biodegradation rate of 8% or more at a detection period of 6 months, and the number average molecular weight of the polyester material at the end of the 2 nd year, which is masked in a natural soil environment, is reduced from that at the beginning of the 1 st year, and has a good degradation property as compared with the existing synthetic polyester.

Description

Preparation method and application of sulfur-containing naturally degradable high molecular weight polyester PES Technical field: The invention belongs to the technical field of synthesis of naturally degradable high molecular materials, and particularly relates to a preparation method of sulfur-containing degradable high molecular weight polyester. Two sulfur-containing organic dibasic acids and dihydroxyl compounds are used as raw materials, and a series of natural degradable novel high molecular weight polyesters are synthesized by a melt polymerization method, so that the novel natural degradable high molecular weight polyesters are used for preparing packaging film materials in the fields of food packaging, fast-food packaging, and the like, and the requirements on high plasticity and degradability are met. The background technology is as follows: With the development of the plastic industry, the synthetic polymer material plays an extremely important role in various fields of industrial and agricultural production and daily life. While environmentally friendly materials and sustainable materials have been important targets for both academic and industrial research. It has been a challenge to study new generation sustainable materials as competitive alternatives to petroleum-based plastics and for these new materials to match them with the performance and cost effectiveness of commonly used petroleum plastics. Due to the accumulation of plastic waste in the last decades, adverse effects on the surrounding environment and human health are created. Unlike small molecule organic waste, plastics may take decades to hundreds of years in nature to degrade, and if nothing is done, by 2050, there will be more plastics in the ocean than fish. Petroleum-based polyesters are polymers obtained by polycondensation of petroleum-derived polyols and polyacids, mainly referred to as polyethylene terephthalate (PET), and conventionally include linear thermoplastic resins such as polybutylene terephthalate (PBT) and polyarylate, have excellent physical properties and chemical stability, are engineering plastics excellent in properties and wide in application range, and can be made into fibers and films. The current worldwide demand for petroleum-based polyesters continues to grow [1], and its main fields of application include the industries of films, fibers, communications, construction, packaging materials, and the like. The polyester industry is currently faced with a number of challenges and difficulties to be resolved. Firstly, the problem of resource supply, because petroleum is used as a main source material and is not a renewable resource, the large-scale use of polyester products inevitably aggravates the shortage of global energy and the exhaustion of resources, and secondly, the problem of environmental impact, polyester waste is difficult to degrade, and long-term environmental pollution and the like [2-4] are caused. With the improvement of living standard and the progress of production technology, the main performance requirements of polyester are more and more strict. In the background of increasing environmental awareness, degradable polyesters are becoming a growing concern and have found wide application [5,6]. [1]Cui Y,Deng C,Fan L,et al.Progress in the biosynthesis of bio-based PET and PEF polyester monomers[J].Green Chemistry,2023,25:5836-5837 [2]Jambeck J R,Geyer R,Wilcox C,et al.Plastic waste inputs from land into the ocean[J].Science,2015,347(6223):768-771. [3]Pellis A,Malinconico M,Guarneri A,et al.Renewable polymers and plastics:Performance beyond the green[J].New Biotechnology,2021,60:146-158. [4]Ma Y,Ji Y,Zhang J,et al.Research advances in vegetable-oil-based pressure-sensitive adhesives[J].Green Materials.2023(11):147-161. [5]Sharma V,Sehgal R,Gupta R.Polyhydroxyalkanoate(PHA):properties and modifications[J].Polymer,2021,212:123161-123191. [6]Zhang Q,Song M,Xu Y,et al.Bio-based polyesters:Recent progress and future prospects[J].Progress in Polymer Science,2021,120:101-430. The invention comprises the following steps: The invention provides a preparation method of high molecular weight biodegradable polyester and application thereof, wherein the polyester has low molecular weight, low melting point, low mechanical property and processing property, the catalyst consumption of a catalytic polymerization system is large, the catalytic polymerization efficiency is low, the color of a polymerization product is deep, the light transmittance is poor, the molecular weight of the obtained polyester is generally only 0.5-2 ten thousand, the indexes of the obtained polyester such as tensile strength, extensibility and the like are low, the tensile property or film forming property is poor, the polyester cannot be processed into food-grade packaging bags, and a high-strength ultrathin polyester film cannot be prepared, so that the effective application of the existing polyester in the field of film prepar