Cross-linking reaction of Wuhan Handern PVC
DATE：2020/7/22 8:42:35 / READ： / SOURCE：This station
Cross-linking reaction of Wuhan Handern PVC
The use of cross-linking methods can overcome these shortcomings and improve the grade of PVC products. PVC cross-linking methods include peroxide cross-linking, radiation cross-linking, silane cross-linking, dimercapto tri-compound cross-linking, copolymerization/grafting and introduction of easy cross-linking group cross-linking methods. Peroxide cross-linked PVC due to two chemical reactions, dehydrochlorination reaction and cross-linking reaction when heated, produces a gel-like insoluble matter. The cross-linking reaction speed is slow and the gel content is low, so it is difficult to obtain practical value. material. Although silane crosslinking is not easy to cause polymer decomposition and chain scission, the chemical reaction is complicated and the processing conditions are harsh. The crosslinking of PVC with dimercaptotriazine compounds and the crosslinking of crosslinkable groups introduced by copolymerization grafting all go through complex chemical reactions, which affect the conditions. The radiation cross-linking efficiency is high, the process conditions are easy to control, and the extrusion process and the cross-linking process are separated, making the radiation cross-linking method widely used. www.handern.com non-woven equipment
Adding multifunctional unsaturated monomers to PVC to sensitize the radiation crosslinking of PVC can improve crosslinking efficiency, reduce main chain scission, and control the degradation of the polymer during radiation. The added multifunctional unsaturated monomers are mainly trimethylol Propane trimethacrylic acid (TMPTMA), trimethylolpropane triacrylate (TMPTA), triallyl isocyanate (TAIC), tetraethylene glycol diacrylate (TEGDA), tripropylene glycol diacrylate ( TPGDA), dipropylene glycol diacrylic acid (DPGDA), etc. www.handern.com non-woven equipment
It is generally believed that the crosslinking mechanism is a free radical crosslinking reaction. The free radicals come from the cleavage of the CC1 and C-H bonds on the PNVC chain, as well as the free radicals generated by multifunctional monomers. The factors that affect the radiation crosslinking of PVC include: plasticizers Type and amount of polymerization degree of base resin, type of crosslinking sensitizer, radiation dose, type and amount of processing aid, type and amount of filler, etc. www.handern.com non-woven equipment
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