Breakthrough progress in PBS research and developm

China has made breakthroughs in the research and development of PBS. This announcement is part of the adjustment progress of the announcement of the Tariff Commission of the State Council on imposing tariffs on imported goods originating in the United States of $50billion (announcement [2018] No. 5 of the Tariff Commission) released by the Tariff Commission of China on June 16.

polybutylene succinate (PBS) entered the field of material research in the 1990s, It has quickly become one of the hot research materials of general biodegradable plastics that can be widely used. Compared with PCL, PHB, PHA and other degradable plastics, PBS is extremely cheap, the cost is only 1/3 or even lower than the former, and it has good heat resistance. The thermal deformation temperature and the service temperature of products can exceed 100 ℃. The source of synthetic raw materials can be either petroleum resources or biological resources fermentation, so it has attracted great attention of science and technology and industry. With the efforts of the National Engineering Research Center for engineering plastics of the Institute of physical and chemical technology of the Chinese Academy of Sciences, a breakthrough has been made in the comprehensive research of PBS in China from synthesis, modification to product processing and application, which has laid a good foundation for the promotion and application of biodegradable materials in China

pbs is obtained by polycondensation of succinic acid and butanediol. PBS synthesized by traditional succinic acid and butanediol polycondensation has a relative molecular weight of less than 5000 and can be used as a gas chromatography stationary phase or plasticizer. However, due to its low relative molecular weight and poor mechanical properties, it is difficult to be used as a material. In the mid-1990s, Showa polymer company of Japan used isocyanate as chain extender to react with low molecular weight PBS synthesized by traditional polycondensation to prepare high molecular weight PBS with a relative molecular weight of 200000. At present, each blowtorch produced by the company with chain expansion method should be equipped with accurate devices to control the propane and air inflow rate of 3000 tons/year, and a new production line with an annual output of 20000 tons is under construction

the National Engineering Research Center for engineering plastics of the Institute of physical and chemical technology of the Chinese Academy of sciences began to develop biodegradable materials in the late 1990s according to the market demand at that time, and in 2002, with the support of the material innovation project of the Chinese Academy of Sciences, it carried out all-round research from PBS synthesis and modification to product processing and application, and has made breakthrough progress at present

in view of the low relative molecular weight of PBS obtained by the polycondensation of traditional succinic acid and butanediol, which is difficult to be used as a material, the center has developed a composite high-efficiency catalytic system of Ti Sn supported on special nano microporous carrier materials, which has greatly improved the catalytic activity of the catalyst. On this basis, PBS with high relative molecular weight was directly polymerized by using the new process of two autoclaves of pre polycondensation and vacuum polycondensation. This innovative process can not only obtain PBS with a relative molecular weight of more than 200000 as the chain expansion method, but also has obvious advantages in process flow and sanitation

compared with the chain expansion method, direct polymerization saves the chain expansion reaction steps, simplifies the production process, eliminates the need for chain expansion reactors and chain expansion processes in the production line, reduces material consumption and equipment investment in the production process, and reduces material production costs. In addition, because the product does not contain isocyanate chain extender, the sanitary performance has been significantly improved. Due to the structural characteristics of isocyanate with certain biological toxicity, the hygienic performance of its products has been seriously affected. Therefore, the promotion of chain extension PBS materials clearly indicates that it is not recommended to be used in areas with strict hygienic requirements such as food, drugs, cosmetics and so on. However, at present, the most waste that leads to white pollution comes from food, which constitutes a burden and burden of Anyang's economic development among the people of the city. Cognitive contact products, such as disposable catering products, food packaging and supermarket shopping bags, will seriously affect the application of degradable materials if the hygienic performance of degradable plastics cannot meet the requirements of food contact. This product of the center is obtained by direct polymerization and does not contain any chain extender. The hygienic performance of the product has been tested and recognized by the Chinese Academy of preventive medicine and the Chinese Center for disease control, and it is completely in compound contact with the national standard requirements of food. At present, this technology has formed two national invention patents, "method for preparing aliphatic dibasic acid diol ester" and "method for preparing polybutylene succinate", forming independent intellectual property rights

in the process of vacuum high-temperature polymerization of butanediol, tetrahydrofuran, a by-product of cyclization reaction such as butanediol in the polymerization process, is inevitably encountered. At present, the conventional solution is to use a special corrosion-resistant vacuum pump. However, the investment in relevant implementation is very large, and a waste of by-products. Therefore, focusing on technology integration, the center creatively introduced a cold trap into the production line, and condensed the by-product tetrahydrofuran brought out with vacuum pumping through the cold trap, which not only solved the corrosion of the vacuum system by the by-product and high equipment investment, but also recovered the by-product tetrahydrofuran

the acceptance experts of the Beijing material base organization of the Chinese Academy of Sciences, including many academicians, spoke highly of the PBS related achievements and technologies developed by the center. The related technologies and achievements have also passed the new technology appraisal organized by the Shandong Provincial Science and Technology Commission, which is considered to have reached the international leading level

the center also carried out research on modification in the kettle, alloying, filling with organic and inorganic fillers, developed a series of PBS degradable plastics, and studied the injection molding, extrusion, blistering, film blowing and other processes of this series of materials. It has been proved that it is suitable for various processing methods and the preparation of various plastic products. This research laid a foundation for the application of degradable materials and the development of products, and also provided technical preparation for the industrialization of biodegradable plastic products in the real sense

at present, PBS has been verified by 10000 ton production units, and relevant technologies have also attracted great attention from the industry. Yangzhou grace, the leading enterprise in the development of polyester facility engineering in China, has reached an agreement with the center for technical authorization to produce 20000 tons of PBS series resin per year. Shanghai Shenhua Group, Fujian Hengan Group and other enterprises have also effectively developed the application and promotion of PBS in the field of disposable packaging products and sanitary products. In addition, some enterprises in New Zealand, Singapore and South Korea have also shown high interest in PBS series materials and products in China. The PBS degradation supermarket shopping bags developed by the project team have been recognized by relevant institutions in New Zealand and Singapore. PBS products prepared in Shanghai Shenhua Group have been used in Shanghai, and the modified material extruded sheets produced have been officially exported to South Korea in small quantities, It provides an effective way to break through the embarrassing situation of semi degradable or projects without market and materials without products formed in China's degradable plastic industry for many years

information source: China chemical industry news

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