梳状液晶高分子材料的合成与性能的研究.rar

摘要：本课题首先合成含偶氮苯基团的甲基丙烯酸酯类单体，含溴甲基丙烯酸酯类单体；采用RAFT聚合技术，以偶氮二异丁氰(AIBN)作为引发剂，а-二硫代萘甲酸异丁腈酯(CPDN)为链转移剂，对甲基丙烯酸甲酯与含溴甲基丙烯酸酯类单体共聚合出侧链含溴的功能性聚合物，制备出分子量可控，分子量分布较窄的聚合物。对制得聚合物作为大分子引发剂，在催化剂CuBr/PMDETA催化下，进行ATRP的偶氮苯单体聚合，将偶氮苯单体成功的引入到聚合侧链中，控制反应时间，制备出不同分子量的侧链型偶氮苯聚合物，利用不同手段纯化聚合物的梳状结构。在聚合过程中显示出了“活性”/可控特征。通过气相色谱（GC）和凝胶渗透色谱（GPC）测试表明：聚合过程呈现出一级动力学特征，聚合物分子量随转化率提高而线性增加，并且分子量分布逐渐变窄；通过差示扫描量热法(DSC)和偏光显微镜，发现聚合物具有较高的稳定性和一定的液晶性；最后，通过紫外分光光度计（UV-VIS），我们研究了聚合物的光致顺反异构化行为和动力学，得到了侧链偶氮苯聚合物的光致反-顺异构化速率常数ke，0.1032s-1；还研究了聚合物在光照和加热条件下的回复行为，得到了侧链偶氮苯聚合物的光致顺反异构化速率常数kh，0.00461s-1。

关键词：侧链偶氮苯聚合物；顺反异构化；结晶性；液晶

Abstract：In this topic , one azobenzene monomer and one bromine containing monomer was first prepared.And then one functionalized polymer with bromine on its side chain was synthetized by using the methyl methacrylate and brominated  monomers, via RAFT polymerization using CPDN as the RAFT agent and AIBN as an initiator.last,the azobenzene monomers was inserted in the side chain of the polymer,via ATRP polymerization under the catalysis of CuBr. different molecular weight  polymers were prepared by controlling the Polymerization reaction time. Various methods were used to purified the polymer.the polymerization process showed well controlled. By the GPC,it was find that the polymerization process presented one-orde dynamics characteristic ,Polymer molecular weight increased linear increase with the conversion rate. At the same time molecular weight distribution gradually narrowed. We also finded that the polymer we prepared has slightly Thermal stabilityand some crystalline. Last, we studied the optical trans-cis isomerization behavior and kinetics of the side-chain azobenzene polymers through the ultraviolet and visible spectrophotometer(UV-VIS) , the constant of isomerization rate ke is 0.1032s-1 . We alsostudied the polymer’ Reply behavior by lighting and heating. And get the onstant of cis-tran kh。0.00461s-1.

Key words：side-chain azobenzene polymers; trans-cis-trans isomerization; rystallinity; liquid crystal