为获得主链规整性高且能形成稳定螺旋结构的炔丙酰胺聚合物,实施了单体M1与单体M2的共聚反应。均聚物1不能形成螺旋结构,均聚物2只有在较低温度下才能形成螺旋结构。不同单体1/2比例的聚合体系,其共聚反应均能顺利进行;共聚物产率高于85%、主链规整性很高(顺式含量大于92%)。通过测定紫外-可见吸收谱图表明,共聚物均能形成螺旋结构,并且与均聚物2相比,共聚物所形成的螺旋结构的热稳定性明显改善。
Copolymerizations of two N-propargylamide monomers were performed in the presence of Rh-based catalyst. All the copolymerization with different monomer feed ratios proceeded smoothly, giving eopolymers with high yields and high cis contents. The eopolymers could adopt helical structures, and when compared with the corresponding homopolymers, the obtained copolymers formed helical structures with higher thermal stability; more importantly, the copolymers were fond to have higher helical contents. It is demonstrated that suited pendent group combinations enable the polymer backbones to form ordered helical conformations.