Preparation And Application Of Polysiloxane-polystrene Graft Polylmers Based On RAFT Polymerization And Thiol-ene Click Reaction

For the past few years,living radical polymerization has aroused much concern.People were most interested in Reversible-Addition-Fragmentation-Chain Transfer Polymerization(RAFT).RAFT polymerization is one of the living radical polymerization.And it has following advantages,for example it shows up good tolerance to various functional groups in monomers,solvents and initiators.In addition,it offers control over a wide range of monomers through the use of different classes of chain transfer agents(CTAs).As a result,RAFT polymerlization has become one of the most popular method of polymerization.Polymers prepared by RAFT polymerization usually have the advantages of narrow polydispersity and high monomer conversion rate.RAFT polymerization has been used to synthesize polymers with complex architectures such as block copolymers,stars and hyperbranched polymers.Click chemistry is a new concept of synthesis that was defined by chemist Sharpless in 2001.He described a powerful organic reaction,it has good selectivity,high conversion rate and mild condition.It provided an efficient and simple synthesis method for later researchers.The introduction of click chemistry has made great contributions to chemical synthesis,molecular biology and drug development.Organic silicon materials have a variety of excellent performance,such as excellent high and low temperature resistance,ozone and aging resistance,weather resistance,excellent dielectric performance and good physiological inertia.Therefore,it has been widely used in many fields.However,it still has some inevitable defects,such as weak mechanical strength,high cost and poor solvent resistance,which limits its use in some fields.But using organic silicon polymer and organic polymer to copolymerize can make up the defect of organic silicon polymer.The main work in this paper includes the synthesis of RAFT chain transfer agents,polystyrene was prepared with one of the chain transfer agents and then the graft copolymer of polysiloxane and polystyrene was prepared by thiol-ene click reaction.In addition,we investigated the influence of molecular weight of polysiloxane,vinyl content and the molecular weight of polystyrene on the experimental results.The graft polymer was then vulcanized with peroxide.We investigated the damping property of vulcanized rubber.Finally we use it as compatibilizer,synthesis of PS/PDMS thermoplastic dynamic vulcanizate was studied.