星形多臂丁苯共聚物的分子结构设计与合成

Molecular structure design and synthesis of star-shaped multi-arm styrene-butadiene copolymer

以正丁基锂为引发剂、苯乙烯与丁二烯为单体、双四氢糠丙烷为极性结构调节剂、六氯乙硅烷为偶联剂,采用活性负离子聚合技术设计并合成了一系列具有星形结构的多臂丁苯共聚物(S-g-SSB-6)。使用凝胶渗透色谱分析了S-g-SSB-6的分子量及其分布、偶联臂数和偶联效率,使用旋转流变仪测试了S-g-SSB-6、以SiCl_(4)为偶联剂的星形多臂丁苯共聚物及线型结构丁苯共聚物(L-SSB)的流变性能,并考察了支链长度和支链柔顺性对S-g-SSB-6流变性能的影响。结果表明,S-g-SSB-6的偶联臂数达到4.1、偶联效率均大于80%;相同重均分子量下S-g-SSB-6的熔体黏度较L-SSB更低、流体流动性更好;当支化度相同时,S-g-SSB-6的熔体黏度随着单臂分子量和分子链刚性的增加而增大。

A series of star-shaped multi-arm styrene-butadiene copolymers(S-g-SSB-6)were synthesized by living anionic polymerization,with n-butyllithium as initiator,styrene and butadiene as monomers,2,2-di(tetra-hydrofuran-2-yl)propane as polar structure regulator and hexachlorodisilane as coupling agent.The molecular weight and its distribution,coupling arm number and coupling efficiency of S-g-SSB-6 were characterized by gel permeation chromatogram.The rheological properties of S-g-SSB-6,star-shaped multi-arm styrene-butadiene copolymer with SiCl_(4) as coupling agent,and linear styrene-butadiene copolymer(L-SSB)were characterized by rotational rheometer,and the effects of branched chain length and branched chain flexibility on the rheological properties of S-g-SSB-6 were also investigated.The results showed that the coupling arm numbers of S-g-SSB-6 reached 4.1,and the coupling efficiency was greater than 80%.S-g-SSB had lower melt viscosity and better fluid flow than those of L-SSB under the same weight-average molecular weight.When the branching degree was the same,the melt viscosity of S-g-SSB-6 increased with the increase of single arm molecular weight and molecular chain rigidity.