Study On Anionic Polymerization Of Butadiene, Isoprene, Styrene In Presence Of Asymmetric Ethers And TMEDA

The key technology in developing binary structure solution styrene and butadiene rubber (SSBR) is the study on new modifiers. Symmetric ether modifiers in general use can not fufill high content of 1,2-structure and high coupling efficiency of polymer in both. Aiming at this crux problem, eight kinds of asymmetric ether modifiers, glycol butyl s-butyl ether (GBSE), glycol butyl i-butyl ether (GBIE), glycol butyl cyclohexanely ether (GBCE), glycol butyl phenyl ether (GBPE), 2-(N,N- diethylamino)ethyl butyl ether(ABE), 2-(N,N-diethylamino)ethyl s-butyl ether(ASBE), 2-(N,N- diethylamino)ethyl /-butyl ether(AIBE), diethylene glycol 2-(N,N- diethylamino)ethyl butyl ether (GABE) are synthesized following the Williamson method in this thesis. The synthesized asymmetric ether modifiers are used in anionic polymerization of butadiene. It is found that GABE is the strongest modifier in terms of the regulating polymerization rate and microstructure of polymer. Furthermore, the effects of GABE on polymerization kinetics, microstructures of polymer and coupling reaction in the copolymerization of butadiene and styrene are investigated thoroughly. With the increase of the amount of GABE, the homopolymerization and copolymerization rate of butadiene and styrene increase and the 1,2-structure content of polymer also increases and reaches up to over 70%. With the increase of polymerization temperature, the homopolymerization rate of butadiene increases; the homopolymerization rate of styrene passes through a maximum, the copolymerization rate of butadiene and styrene increases and the 1,2-structure content of polymer decreases. GABE does not affect the coupling reaction of butadiene and styrene copolymer. With the same amount of modifiers (A/Li=1.0) the coupling efficiency in the case of GABE can reach up to about 50 %, which is much higher than the coupling efficiency of 5% using 2G that is a modifier mostly used right now. GABE can fully satisfy the request for modifiers used to prepare the binary structure solution styrene and butadiene rubber with low rolling resistance and good wet traction, which will provide good technical support for the development of binary structure SSBR in China.The composition of "integral rubber" styrene, isoprene and butadiene rubber(SIBR) with good congregative property is complex. The fundamental study about the effect of modifiers on polymerization kinetics, the microstructure and composition distributation of polymer is so scarce. The industrial development of SIBR is restricted. In this thesis, theanionic polymerization of butadiene, isoprene, styrene with N,N,N',N'-tetramethylethylenediamine (TMEDA) as modifier is also studied in detail. The variation trends about effects of TMEDA and polymerization temperature on polymerization kinetics of homopolymerization, copolymerization and terpolymerization, microstructure of polymer, composition distribution of copolymer are investigated. With the increase of the amount of TMEDA, the homopolymerization rate of butadiene increases; the homopolymerization rate of isoprene decreases; the homopolymerization rate of styrene goes through a maximum, while the copolymerization rates of butadiene and isoprene, butadiene and styrene increase; the copolymerization rate of isoprene and styrene decreases; the terpolymerizaton rate of butadiene, isoprene and styrene passes through a maximum. As the polymerization temperature increases, both the homopolymerization and copolymerization rates increase. The experimental equations between the 1,2-sructure content of polybutadiene and the 1,2+3,4-structure content of polyisoprene with the ratio of TMEDA/Li are obtained. The method for regulating the microstructure of polymer is developed. The monomer reactivity ratios of butadiene, isoprene and styrene in copolymerization are acquired by the advanced TM method. The copolymerization and terpolymerization kinetics and composing distribution of copolymer are simulated and calculated. It is found that the predicated value and experimental value are in good agreement. The copolymerization and terpolymerization kinetics and composing distribution of copolymer can be predicted very well and it will lay solid foundation for preparing SIBR.