Polyvinyl chloride (PVC) is the initiator of peroxides and azo compounds in vinyl chloride monomer (VCM). Or under the action of
light and heat according to the mechanism of free radical polymerization polymerization polymer. Vinyl chloride homopolymer and
vinyl chloride copolymer are called vinyl chloride resin.
PVC for amorphous structure of white powder, branched degree is small, relative density 1.4, glass transition temperature of 77 ~
90 ℃, 170 ℃ or so began to decompose, poor stability to heat and light, in more than 100 ℃ or the sun for a long time, will
decompose and produce hydrogen chloride, and further automatic catalytic decomposition, cause discoloration, physical and
mechanical properties also fell rapidly, In practice, stabilizer must be added to improve heat and light stability.
The molecular weight of PVC produced by industry is generally in the range of 50,000 ~ 110,000, which has great polydispersity,
and the molecular weight increases with the decrease of polymerization temperature. There is no fixed melting point, it begins to
soften at 80~85℃, becomes viscoelastic state at 130℃, and becomes viscous flow state at 160~180℃. Has good mechanical properties,
tensile strength about 60MPa, impact strength 5~10kJ/m2; It has excellent dielectric properties.
PVC used to be the world's largest general-purpose plastic and was widely used. It is widely used in building materials,
industrial products, daily necessities, floor leather, floor brick, artificial leather, pipe, wire and cable, packaging film,
bottle, foaming material, sealing material, fiber and so on.