摘要
用激光光散射和粘度法研究了一系列窄分子量分布的新的手性甲壳型液晶聚合物P1～P6的溶液行为及其链刚性.研究发现四氢呋喃是聚合物P1～P6的良溶剂.在四氢呋喃溶液中,聚合物P1～P6的特性粘数[η]和均方根旋转半径<Rg2>z12对重均分子量Mw的依赖关系分别是[η]=(2.75±0.05)×10-3Mw0.78±0.02和<Rg2>z12=(1.53±0.04)×10-2Mw0.60±0.01.按照YamakawaFujiiYoshizaki蠕虫状圆筒模型的粘度理论和BohdaneckyBushin表达式,求得聚合物的单位围长摩尔质量ML=(29.8±1.0)×102nm,构象保持长度q=(15.4±3.0)nm.q和MHS方程指数α的值说明这类在结构上属于侧链型液晶高分子的聚合物在良溶剂四氢呋喃中呈现比较伸展的刚性链构象,其链刚性与半刚性主链液晶高分子的相似.
A series of optically active mesogen-jacketed liquid crystal polymers with narrow polydispersities （P-1 ～ P-6） were studied by a combination of static and dynamic laser light scattering techniques and viscosity measurements in THF at 25 ℃. It is found that THF is a good solvent for the polymers studied. The dependences of the intrinsic viscosity [ η ] and root mean-square radius of gyration 〈 Rg^2 〉z^1/2 of the polymers on weight-average Mw are [η]=（2.75±0.05）×10^-3 Mw^ 0.78±0.02 and 〈Rg^2〉z^1/2=（1.53±0.05） ×10^-2 Mw^0.60±0.01 ,respectively, in THF at 25℃. According to Bohdanecky-Bushin s method based on Yamakawa-Fujii- Yoshizaki＇s theory for worm-like chain cylinders,the molar mass per unit contour length ML and the persistence length q were estimated to be （29.8 ± 1.0） × 10^2 nm and （15.4 ± 3.0） nm, respectively. The values of the exponent a of Mark-Houwink-Sakurada equation and q indicate that these liquid crystal polymers of the side-chain type have an extended conformation in dilute solutions as most main-chain liquid crystal polymers.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2005年第5期774-778,共5页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号20274001
20134010)
国家杰出青年科学基金(基金号20325415)
教育部科学技术研究研究重点项目(项目号01001)资助项目
