Basic Technology Of Molecular Material Of PVC Wall Panels
Polyvinyl chloride is formed by the polymerization of VCM through free radicals. Suspension polymerization method, emulsion polymerization method and bulk polymerization method were mainly composed of suspension polymerization, which accounted for about 80% of PVC total production. Sources of monomer: ethylene, petroleum and calcium carbide. China's methods: mainly calcium carbide method.PVC Wall Panels The suspension polymerization method was used to disperse the monomer in the water phase by the micro-droplet. The oil soluble initiator is dissolved in monomer, polymerization reaction is carried out in these droplets, the polymerization reaction heat is absorbed by water in time, in order to ensure that these droplets are dispersed in bead form in water, we need to add suspending stabilizer, such as gelatin, polyvinyl alcohol, methyl cellulose, Hydroxyethyl cellulose and so on.
The initiator uses organic peroxide and azo compounds, such as peroxide, dimethyl carbonate, two cyclohexyl carbonate, diethyl peroxide, dimethyl carbonate and azo nitrile, and so on, which are used in many different fields. Polymerization is carried out in a polymerization kettle with a blender. After polymerization, the material flows into the monomer recovery tank or the stripping tower. Then into the mixing kettle, washed and then centrifugal dehydration, drying is the resin finished product.PVC Wall Panels
In emulsion polymerization, in addition to water and vinyl chloride monomer, also need to add alkyl sulfonate and other surfactants as emulsifier, so that the monomer dispersed in the water phase and milk liquid, to water-soluble potassium sulfate or ammonium persulfate as initiator, can also be used "oxidation-reduction" initiation system, polymerization process and suspension method is different. Also have added polyvinyl alcohol as emulsifying stabilizer, 12 alkyl mercaptan as the regulator, sodium bicarbonate as buffer agent.PVC Wall Panels The polymerization method has three kinds of intermittent method, semi-continuous method and continuous method. The polymerization product is latex-like, emulsion particle size 0.05~2μm, can be directly applied or spray-dried into powdered resin. Emulsion polymerization period is short, easy to control, the resin molecular weight is high, the polymerization degree is homogeneous, suitable for making PVC paste, making artificial leather or impregnated products.PVC Wall Panels