From the biodegradation process is divided into complete biodegradability and biological collapse of the two categories of plastic; from the preparation method can be divided into biological fermentation synthesis, chemical synthesis, the use of animal and animal natural macromolecules or minerals four.
Completely biodegradable plastics are easily degraded when they are chemically synthesized using aliphatic polyester, polyvinyl alcohol (PVA) and polyethylene glycol. The biodegradable properties of these polymers are used to study and develop biodegradable plastics, and the research on aliphatic polyester is very prominent. Polyethylene lactone (PCL) is widely used in a wide range of aliphatic polyesters. It is a thermoplastic crystalline polyester that can be hydrolyzed into small molecules by lipases and then further assimilated by microorganisms. US UCC company has been mass production, and has been used for surgical supplies, adhesive film, release agent and other products. After blending PCL with PHB, biodegradable plastics can also be prepared. Alkaline polyester and nylon for the exchange reaction of amine, synthetic polyacrylate copolymer (CPAE), CPAE is a new type of biodegradable plastic.
In the synthesis of natural macromolecules with plants and animals, the plant cellulose, starch, animal chitosan, polyglucose, animal glue and marine organisms such as algae can produce valuable biodegradable plastics.
Can also use chemical methods and natural polymer blending technology to synthesize biodegradable plastics, the main varieties are PHB / PCL, gelatinized starch / PCL and other products. Their main feature is the complete degradation of the same time through the blending to improve its heat resistance, water resistance and reduce costs, making it a common degradation of plastic.
Biocompatible plastic is an incomplete biodegradable plastic, is mixed with biodegradable materials in the olefin plastic, the material loss of mechanical properties and shape, and by composting and biodegradability performance of the same effect, because such plastic Low cost, domestic and foreign have adopted this method.
The aliphatic polyester bioformed plastic is a very slender fibrous uniform dispersion of a general plastic to a biodegradable polyester which enables biodegradability of the copolymer. The plastic compounds such as PE, PP, PS, PVC and other blends are used to control the phase structure and dispersion state, and the biodegradable plastic with excellent physical properties is obtained. The natural mineral biological collapse plastic and calcium carbonate filled modified poly Olefin plastic similar, in order to meet the needs of the environment, research and development of high-filled calcium carbonate masterbatch and special materials, as a film, sheet, box and other packaging materials. Jilin Institute of the study of PE / calcium carbonate degradation of materials. This kind of material has the advantages of low plastic consumption, low energy consumption and low cost, but it is short of the density, low air tightness, unfavorable degradation period and poor mechanical performance, so it can only be used as a one-time packaging material, Its degradation is yet to be further studied.
Biodegradable plastic development direction is A, the use of cellulose, starch, chitin and other polymer materials to produce biodegradable plastics, and further development of improved natural polymer function and technology. B, the use of polymer design, fine synthesis of synthetic biodegradable plastics. The biodegradable plastics were prepared by analyzing the biodegradation mechanism of biodegradable synthetic polymers. At the same time, the copolymerization of these macromolecules with existing general polymers, natural macromolecules and microbial polymers was studied. Development; C, to improve the biodegradable properties of biodegradable plastics and reduce its costs, and widen the application. D, Degradation Rate Control. In short, with the needs of society, biodegradable plastics will be more and more attention, as the next period of a major research topic.
PHA degradation of plastic is biodegradable plastics in the performance of the most excellent, and because of its high cost, the production process is more complex, is still in the initial stage of the market. In 2010, the global PHA production capacity of less than 80,000 tons, of which the United States Metabolix company has about 50,000 tons of production capacity, accounting for more than 60% of the market. Chinese enterprises in the PHA production process and research and development on the same go ahead, Tianjin Guoyun Biomaterials Co., Ltd. has 10,000 tons of PHA production capacity, Ningbo Tianan has 2,000 tons of production capacity, Shenzhen Italian Keman Biological Technology Co., Ltd. has 5000 Ton of capacity. Japan's Kaneka Corporation, Brazil's PHB Industrial Corporation is also a typical representative of the PHA industry, these companies are PHA industry promoters, although the current PHA application is more limited, resulting in Metabolix annual actual sales of not more than 100 tons, but With the gradual expansion of the future application of the downstream, especially in the film packaging, plastic sheeting, food utensils, nonwovens and other industries to further mature, PHA market potential.