The Synthesis And Properties Of Integral Rubber PSI-PIB-PSI

Integral rubber exhibiting excellent low dynamic heating, high wet grip performance and favorable mechanical properties, will lead the direction of advanced tire tread.In this research, we synthesized dilithium initiator of low[THF]/[Li~+] ratio. Then we used this initiator to initiate the anionic polymerization of random PIB, with the butadiene and isoprene as monomers, cyclohexane as solvent. Microstructures, copolymerization composition, glass transition temperature were researched.Using this dilithium initiator as initiator, a new kind of line-shaped tri-block copolymer: Poly (isoprene-ran-styrene) -(butadiene-ran-isoprene) -(isoprene-ran-styrene) were synthesized by two steps continuous anionic polymerization techniques. Microstructures and copolymerization composition of these copolymers were characterized by nuclear magnetic resonance (H-NMR). Morphologies and dynamic mechanical properties were measured by transmission electron microscopy (TEM) and dynamic mechanical thermal analysis (DMTA).The results manifest that dilithium initiator has low[THF]/[Li~+] ratio and high bifunctionality. The copolymers show two phase states, this phenomenon is clearer when the styrene content is higher. The copolymers have an integrative mechanical property when styrene content is 27-28% and PIB/PIS is 1/2.