论文部分内容阅读
通过自由基共聚合制备了一系列L-丙烯酸薄荷酯(L-MtA)与2,5-二(4’-己氧基苯基)苯乙烯(BHPSt)的共聚物L-MtA(x)-co-BHPSt(1-x).利用UV-Vis和1H-NMR光谱表征了共聚物的组成,根据Kelen-Tüds(K-T)方法计算得到的L-MtA和BHPSt的竞聚率分别为0.36和2.46,说明两结构单元在聚合物链中倾向于无规排列.当BHPSt含量较少时,共聚物在三联苯侧基的紫外吸收区呈现明显的Cotton效应,说明某种手性结构的形成;而当BHPSt含量足够大时,共聚物具有和光学活性螺旋链聚{(+)-2,5-二[4’-((S)-2-甲基丁氧基)苯基]苯乙烯}(PMBPS)类似的圆二色光谱,说明BHPSt链段能够形成稳定的螺旋构象,且由于L-MtA单元的手性诱导,其旋向在某一方向占优.
A series of copolymers of L-MtA (x) - L-MtA with 2,5-bis (4’-hexyloxyphenyl) styrene (BHPSt) were prepared by free radical copolymerization. co-BHPSt (1-x). The copolymer compositions were characterized by UV-Vis and 1H-NMR spectroscopy. The reactivity ratios of L-MtA and BHPSt calculated by Kelen-Tüds And 2.46, indicating that the two structural units tend to randomly arranged in the polymer chain.When the content of BHPSt is small, the copolymer shows obvious Cotton effect in the ultraviolet absorption region of the terphenyl side group, indicating that a certain chiral structure is formed ; And when the content of BHPSt is large enough, the copolymer has the same structure as that of the optically active, helical chain poly {(+) - 2,5-bis [4’- ((S) -2-methylbutoxy) phenyl] } (PMBPS), indicating that the BHPSt segment can form a stable helical conformation, and the rotation of the L-MtA unit is dominant in one direction due to the chiral induction of the L-MtA unit.