PVC light, heat stability is poor. Softening point of 80 ℃, begin to decompose at 130 ℃. Without heat stabilizer, polyvinyl chloride 100 ℃ began to decompose, faster decomposition above 130 ℃. Thermal decomposition of the release of hydrogen chloride gas (hydrogen chloride gas is a toxic gas) to make it change color, from white to pale yellow → red → → → dark brown. The sun's ultraviolet light and oxygen causes oxidation and decomposition of PVC occur, thus making flexible PVC decline, finally brittle. From here is not difficult to understand why some PVC plastic over time will turn yellow, brittle reasons. Physicochemical properties of pvc plastic tube having a stable, insoluble in water, alcohol, gasoline pvc pipe, gas, vapor leakage low; at room temperature can be resistant to any concentration of hydrochloric acid, sulfuric acid 90% or less, 50-60% nitric acid caustic soda solution and 20% or less, has a chemical resistance; for salts quite stable, but can be dissolved in ether, ketones, chlorinated aliphatic and aromatic hydrocarbons and other organic solvents. PVC is the biggest characteristic is flame retardant, so it is widely used in fire protection applications. But PVC in the combustion process releases hydrogen chloride and other toxic gases, such as dioxins. PVC combustion in two steps. First at 240 ℃ -340 ℃ combustion and decomposition of hydrogen chloride gas having a double bond diolefin, and then combustion of carbon occurs at 400-470 ℃. It is one of the world's largest production of plastic products, cheap, widely used in polyvinyl chloride resin is white or pale yellow powder. Depending on the use of different additives can be added to the price of pvc pipes, PVC may exhibit different physical and mechanical properties. Adding an appropriate amount of plasticizer in PVC resin can be made from a variety of hard, soft and transparent products. Pure PVC density 1.4g / cm3, adding plasticizers and fillers, such as the density of PVC plastic is generally 1.15-2.00g / cm3. Rigid PVC has good tensile, flexural, compressive strength and impact resistance, can be used as structural materials alone. Soft PVC softness, elongation at break, cold resistance will increase, but the brittleness, hardness ,, tensile strength is lowered. PVC has good electrical insulation properties, can be used for low-dielectric material, its chemical stability or. Due to poor thermal stability of PVC, prolonged heating can cause decomposition and emit HCL gas, discoloration of polyvinyl chloride, so its narrow range of applications, the use temperature is generally between -15 ~ 55 ℃. Qingdao pvc pipe, pvc pipe, sea Widex Widex provided by Qingdao Rubber Material Co., Ltd. Widex Qingdao Rubber Material Co., Ltd. (www.haihuidaxiangsu.com) strong, credible, in Qingdao, Shandong industrial products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the sea Widex and you work into the brilliant, for a better future!