伯胺功能化苯乙烯/丁二烯共聚物合成及其组成分布调控

Synthesis of Primary Amine Functionalized Styrene/Butadiene Copolymer and Contol of Its Composition Distribution

苯乙烯/丁二烯共聚物是一种有广泛应用基础的弹性体材料,对其结构的控制是调控材料性能的关键.对于序列无法精准控制的共聚合体系,需要对其结构进行组成分布控制.本文在伯胺DPE衍生物、苯乙烯和丁二烯的三元共聚合体系中,通过改变投料顺序,合成分子量相近、组成分布不同的伯胺功能化丁苯共聚物(ran-NFSBC和grad-NFSBC),并对聚合动力学开展研究.在ran-NFSBC中,苯乙烯对伯胺DPE衍生物的竞聚率为2.58,伯胺DPE衍生物的转化率为71.7%,且苯乙烯组成为无规分布趋势.在grad-NFSBC中,伯胺DPE衍生物完全转化,并利用定时取样测定其组成分布,苯乙烯组成呈现梯度分布趋势.最后,利用DSC测试初步揭示了组成分布对丁苯共聚物热性能的影响.

The styrene/butadiene copolymer is widely used as elastomer in various applications of packing material,such as shoes,asphalt modifiers,etc.The control of structure is the key to control the properties of material.Living anionic polymerization is still state of the art for the precise preparation of SBC.However,the sequence distribution of the copolymerization of styrene and butadiene cannot be as precise as that of styrene and DPE derivatives,because the product of reactivity ratios of styrene and butadiene is not approximately equal to 0.The composition distribution control was proposed to describe the behaviour of monomers in the statistical anionic copolymerisation.Herein,the primary amine DPE derivative was copolymerized with styrene and butadiene.In the terpolymerization,two primary amine functionalized SBC with similar molecular weight but different composition distributions were synthesized by varying feeding orders(i.e.ran-NFSBC and grad-NFSBC).The kinetics of copolymerizations were calculated.In ran-NFSBC,the reactivity ratio of St to DPE derivative was 2.58.The conversion of primary amine DPE derivative was 71.7%.The composition distribution was random distribution.In grad-NFSBC,the primary amine DPE derivative was totally consumed.The composition distribution was determined to be gradient distribution using the timing sample method.Finally,the relationship between composition distribution and thermal behavior of SBC was preliminarily studied by DSC.