As early as 1889, Gariel and Maass first synthesized polyamide PA66 resin in the laboratory. In 1924, the father of polymer, the German scientist H. Staudinger first proposed the theory of macromolecules. In 1932 he published the first monograph on high molecular organic compounds, and studied the polymer polycondensation reaction and developed polyamide for WH, Carothers. PA66 resin lays the theoretical foundation. China's research on polyamides is relatively late, and the main goal is to provide raw materials for synthetic fibers. In the 1950s, China's first set of PA66 (1000t/a) was built at Jinxi Chemical Plant, and then PA66 production unit was established in Nanjing Chemical Industry Company. In 1959, 300t/a polyamide PA66 was introduced from Germany. And the spinning equipment, established the Beijing Synthetic Fiber Test Factory. In 1964, Tianjin introduced the polyamide 6 production equipment from the former Czechoslovakia. In the mid-1960s, Shanghai Suiyuan Chemical Plant established China's first polyamide 66 salt production unit with a capacity of 600t/a. In 1973, Liaoyang Petrochemical Fiber Co., Ltd. introduced technology and equipment from Ronald Planck, France, to build a 46kt/a polyamide PA66 salt production facility. In the late 1980s, Sinopec Baling Petrochemical Company and Nanjing Oriental DSM Chemical Co., Ltd. introduced caprolactam production technology from Stamicarbon, a DSM subsidiary in the Netherlands. The plant scale was 50 kt/a and was completed and put into operation in 1992. Zhejiang Suihua also built a 4,500 t/a unit using China's own R&D technology. In 1994, Shenma Group (formerly Pingdingshan Cord Fabric Factory) introduced production technology of partial hydrogenation of benzene and polyamide PA66 from Japan's Asahi Kasei Co., Ltd. The actual production capacity of the plant was 60 kt/a, which was completed and put into operation in September 1998. In 1996, Sinopec Shijiazhuang Refining & Chemical Company introduced the technology of producing Sodium benzene from Italy by Snia Company. It was completed and put into production in November 1999.
