2. PVC futures refer to futures varieties with PVC as the subject matter. PVC, that is, polyvinyl chloride, is a thermoplastic resin. It is also called four basic building materials with steel, wood and cement, and five general-purpose resins with PP, PE, ABS and PS, which is the product with the largest consumption of organochlorine in chlor-alkali industry.
First, briefly introduce PVC.
1. Polyvinyl chloride (PVC for short) is the initiator of vinyl chloride monomer (VCM for short) in peroxides and azo compounds. Or a polymer polymerized under the action of light and heat according to a free radical polymerization mechanism.
2.PVC is white powder with amorphous structure, with low branching degree, relative density of about 65438 0.4, glass transition temperature of about 77~90℃ and 65438 070℃, and poor stability to light and heat. When it is higher than 100℃ or exposed to the sun for a long time, it will decompose to produce hydrogen chloride, which will further decompose automatically, causing discoloration.
3. The molecular weight of industrial PVC is generally in the range of 50000 ~ 1 10000, which has great polydispersity, and the molecular weight increases with the decrease of polymerization temperature; Without a fixed melting point, it begins to soften at 80~85℃, becomes viscoelastic at 130℃, and becomes viscous at 160~ 180℃. It has good mechanical properties, the tensile strength is about 60MPa, and the impact strength is 5~ 10kJ/m2. Has excellent dielectric properties.
4. According to the different application scope, PVC can be divided into general PVC resin, high polymerization degree PVC resin and cross-linked PVC resin. Universal PVC resin is polymerized by vinyl chloride monomer under the action of initiator; High polymerization degree PVC resin refers to the resin polymerized by adding chain extender into vinyl chloride monomer polymerization system; Crosslinked PVC resin is a resin polymerized by adding a crosslinking agent containing diene and polyene into the polymerization system of vinyl chloride monomer.
5. According to the methods of obtaining vinyl chloride monomer, it can be divided into calcium carbide method, ethylene method and imported (EDC, VCM) monomer method (ethylene method and imported monomer method are collectively referred to as ethylene method).
I hope I can help you.