【作者】 陈波；

【导师】 张兴英；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2011， 硕士

【摘要】 随着汽车工业的快速发展,对轮胎的各项性能提出了更高的要求。据文献报道,轮胎的滚动阻力有近50%来自胎面胶的滞后损失。平衡轮胎胎面的抗湿滑性和滚动阻力是高性能轮胎的发展方向。通过在聚合物链端接入改性基团可以有效降低自由末端数量,提高聚合物与填料之间的结合力,从而达到在降低滞后损失的同时,改善填料在聚合物基体中的分散能力的目的。本文首先通过正丁基锂与1,1-二苯基乙烯加成反应制备出了改性引发剂1,1-二苯基己基锂(DPHL),并以该引发剂合成出了聚丁二烯、聚异戊二烯、聚苯乙烯以及线性丁二烯-苯乙烯共聚物(SSBR),最后通过SnCl4偶联得到双端改性的星形聚合物。考察了聚合反应时间、端基类型、偶联剂用量、偶联反应温度、偶联反应时间以及分子量对SSBR偶联效率的影响。结果表明：DPHL是有效的阴离子活性聚合引发剂,由其引发合成的线性SSBR,当分子量为7万,n(Cl-)/n(Li+)为1.12,聚合反应时间为60min,偶联温度为60℃,偶联时间30min以上时,偶联效率最高可达74.3%；分子链末端转换为Bd后,可提高偶联效率；随着分子量增大,偶联效率降低。对硫化胶力学性能的研究表明：相比于由正丁基锂合成的星形SSBR,由DPHL合成的链端含有两个大体积苯环的SSBR物理机械性能优异,与填料的相互作用更强,Payne效应最小,硫化胶在0℃时的tanδ最高,60℃时的tanδ最低,表现出了高的抗湿滑性和低的滚动阻力,实现了对SSBR各项性能的改进,更适合用于高性能绿色节能轮胎的胎面用胶。更多还原

【Abstract】 With the rapid development of automobile industry, high performance tires was demanded. It was reported that 50% of rolling resistance is caused by hysteresis loss of the tread rubber. Balancing wet skid resistance and rolling resistance of tire tread is the development direction of high-performance tires. The hysteresis loss and heat generation can be reduced by modifying the macromolecular chain end. Moreover, the interaction between polymer and fillers and the filler dispersion in the matrix can be improved by this way.1,1-Diphenylhexyllithium(DPHL)was firstly prepared by n-butyllithium and 1,1- diphenylethlene through addition reaction. Then linear-shaped polybutadiene, polyisoprene, polystyrene and styrene-butadene copolymer(SSBR) were synthesized using DPHL as initiator, and finally, SnCl4 was added as coupling agent to react with living polymer chains to prepare star-shaped polymers. Coupling efficiency(E) of SSBR was measured. The effect of polymerization time, structure of the end, amount of SnCl4, coupling reaction temperature, coupling reaction time and molecular weight on E were investigated. Physical properties and mechanical properties of the vulcanizates were measured. The results showed that DPHL was an effective living ionic polymerization initiaor and the coupling efficiency could reach to 74.3% when using the optimal reaction conditions as follows:the molecular weight of 7.0×104, n(Cl-)/n(Li+) of 1.12, polymerization time of 60 minutes, coupling reaction temperature of 60°C, coupling reaction time of more than 30 minutes. The E would be higher when convert the chain end to butadiene. Research of mechanical properties of the vulcanizates showed that:Compared with SSBR initiated by n-butyllithium, SSBR initiated by DPHL appeared excellent physical and mechanical properties, stronger interaction with filler, lower Payne effect, and most importantly, exhibited higher 0°C tanδand lower 60°C tanδ, which means higher wet skid resistance and lower rolling resistance. This modified SSBR can be used as high-performance green energy saving tire tread rubber.更多还原