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Plastics using starch: The technology to produce degradable plastics by mixing aliphatic polyester and starch has also been successfully studied. Starch is very important as a direct or indirect raw material for the production of degradable plastics. In addition to corn and sweet potatoes, starches such as cassava, sago palm, and taro can also be used. In European and American countries, the mixture of gelatinized starch and aliphatic polyester is widely used to produce garbage bags and other products. As long as the starch has water, it will gelatinize after heating and is plastic. However, its disadvantage is that it has no water resistance. By controlling the structure of gelatinized starch and PCL, a mixture with excellent water resistance and mechanical properties can be obtained.
According to different uses and environmental conditions, further deepening research, improving formulas through molecular design research, and developing punctual and controllable environmentally degradable plastics have become key research topics in many countries. After summarizing various literatures, the future research and development trends of degradable plastics can be roughly predicted:
Actively research and develop high-efficiency and low-cost photosensitizers, etc., to further improve controllability, rapid degradation and complete degradation.
It is conducive to the treatment of disposable plastic waste, while ensuring that a rich source of raw materials is obtained. Using natural polymers, microbial synthetic polymers and biodegradable synthetic polymers as raw materials, the development of fully biodegradable plastics has attracted more and more attention.
In order to accelerate the development of degradable plastics, countries are working to accelerate research and establish a unified definition, degradation mechanism, evaluation methods and standards for degradable plastics.
Explore and cultivate strains that can degrade ordinary plastics, so that the widely used ordinary plastics are easily degradable after use to meet environmental protection requirements; at the same time, great attention is paid to cultivating biological plants that can produce polyester to reduce the cost of biodegradable plastics. , Is conducive to popularization and application.
In addition, Huang Xudong of Sichuan Union University and others have made the following prospects in the two aspects of material synthesis and processing in the research of biodegradable plastics:
First, material synthesis uses microbial synthesis methods to prepare biodegradable polymers, such as establishing some new models and concepts, using microbial fermentation to obtain polymers with new structures; recycling agricultural raw materials, and developing efficient preparation of bacterial polymers The way; the use of enzymes to catalyze polymers to synthesize new materials; the use of enzymes’ stereoselective monomers to synthesize and modify biopolymers under the action of enzymes.
Use organic synthesis methods to prepare biodegradable polymers, such as synthetic polymers similar in structure to natural polymers, and establish the relationship between polymer structure, morphology, and biodegradability; combine lactones, epoxy compounds, and cyclic Carbonate, anhydride, etc. undergo ring-opening polymerization to obtain new biodegradable polymers; polysaccharides are modified to obtain new degradable processing materials.
Second, develop new technologies for processing and blending to prepare biopolymer derivatives; use reactive processing methods to obtain new biodegradable materials such as polysaccharides and degradable polyesters; develop co-extrusion technology to expand hydrophobic polymerization The application of substances; establish the blending composition to optimize the performance, biodegradability and production cost; blend the degradable plasticizer with the biodegradable polymer to improve the processing performance of the latter and obtain the degradable blended material; Degradable plasticizers, fillers and polysaccharides are blended with degradable polyester to improve processing performance and reduce costs; study the effects of blending ratio, compatibility, morphology, etc. on the dynamics, physical and chemical properties of biodegradable blends influences.