Polyvinyl chloride, PVC, is a polymer formed by vinyl chloride monomer (VCM) in peroxide, azo compounds or polymerization mechanism of radical polymerization under light and heat. Ethylene chloride homopolymer and vinyl chloride copolymer system are called vinyl chloride resin. PVC was once the world's largest versatile plastic product and is widely used. It is widely used in building materials, industrial products, daily necessities, floor leather, floor brick, artificial leather, pipe material, wire and cable, packaging film, bottles, foam materials, sealing materials, fiber and other aspects. According to the different scope of application, PVC can be divided into: general type PVC resin, high polymerization PVC resin, cross-linked PVC resin. General type PVC resin is formed by the polymerization of vinyl chloride monomer under the action of initiator; high polymerization PVC resin refers to the polymer of polymerization system; and crosslinked PVC resin is composed of a crosslinking agent containing diene and polyene in the vinyl chloride monomer polymerization system. According to the acquisition method of ethylene chloride monomer, it can be divided into calcium carbide method, ethylene method and imported (EDC, VCM) monomer method (ethylene method and imported monomer method is habitually called ethylene method). According to the polymerization method, PVC can be divided into four categories: suspension method PVC, emulsion method PVC, bulk method PVC, solution method PVC. Suspension PVC is the largest yield, accounting for about 80% of the total PVC. Suspension method of PVC is divided into six models: XS-1, XS-2..., XS-6; XJ-1, XJ-2..., XJ-6. The meaning of each letter in the model: X-suspension method; S-loose type; J-tight type. According to the content of plasticizer, PVC plastic ene plastic is often divided into: no plasticizer PVC, plasticizer content is 0; hard PVC, plasticizer content is less than 10%; semi-hard PVC, plasticizer content of 10-30%; soft PVC, plasticizer content of 30-70%; polyvinyl
Post time: Jul-29-2022