Natural polymer processing stage. This period was chara […]
Natural polymer processing stage. This period was characterized by the modification and processing of natural polymers, mainly cellulose. In 1905, Bayer AG in Germany industrialized. During this period, some chemists synthesized a variety of polymers in the laboratory, such as novolacs, polymethyl methacrylate, polyvinyl chloride, etc., which laid the foundation for the development of the plastics industry.
Synthetic resin stage. This period is characterized by the production of plastics based on synthetic resins. In 1909, American L.H. Baekeland made a breakthrough in the synthesis of resin with phenol and formaldehyde, and obtained the patent for the first thermosetting resin, phenolic resin. In the phenolic resin, after the filler is added, it is hot pressed into a molded article, a laminate, a coating, an adhesive, and the like. This is the first fully synthetic plastic. Before the 1940s, phenolic plastics were the most important plastics, accounting for about two-thirds of plastic production. Mainly used in the electrical, instrumentation, machinery and automotive industries.
In 1929, American chemist W.H. Carothers proposed the theory of polycondensation, which laid the foundation for the development of polymer chemistry and plastics industry. At the same time, due to the rapid development of the chemical industry at the time, the plastics industry provided a variety of polymer monomers and other raw materials. At that time, Germany, the most developed chemical industry, was eager to get rid of the situation of relying heavily on natural products to meet various needs.
These factors have strongly promoted the development of synthetic resin preparation technology and processing industry. During the great development phase, the output of general-purpose plastics increased rapidly during this period. Polyolefin plastics were put into production in the 1970s with polybutene-1 and poly-4-methyl-1-pentene. Formed the world's largest production of polyolefin plastic series. At the same time, a variety of high-performance engineering plastics have emerged. Developed a new range of high performance engineering plastics. Such as polyoxymethylene, polycarbonate, ABS resin, polyphenylene ether, polyimide and the like.
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