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What is unsaturated polyester resin cross linking network structure´╝č

Jan 22, 2019


The double bond in unsaturated polyester and the double bond in crosslinking agent polymerize to form an insoluble and infusible crosslinking network, which contains two kinds of polymer molecular chain structure.

The double bond in unsaturated polyester and the double bond in crosslinking agent polymerize to form an insoluble and infusible crosslinking network, which contains two kinds of polymer molecular chain structure.The main body of the network is composed of random clusters of unsaturated polyester molecular chains, which are interspersed with styrene copolymer molecular chains. The unsaturated polyester molecular chains are connected and fixed to form a huge network.The average molecular weight of unsaturated polyester chain in the net is 1000~3000.The average molecular weight of styrene copolymer molecular chain can reach 8000~14000.The average molecular weight of the whole network structure is 10000~30000.If the molecular weight of the network is less than 10000, it will directly affect the mechanical properties of the product, such as strength, elasticity and toughness.

Long life free radical unsaturated polyester resin crosslinking network in the curing process, the unsaturated polyester and styrene double bond polymerization process and residual rate changes have certain characteristics.The experiment shows that no matter whether the polyester resin crosslinking network is perfect or not, it will produce some dead points of steric hindering which can not be terminated by free radicals and form long-life free radicals.Due to the existence of long-lived free radicals, the cross-linking reaction of unsaturated polyester resin can still be carried out after curing.


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