乙基氰乙基纤维素/聚丙烯酸复合物的形态结构

乙基氰乙基纤维素(ECEC)溶于丙烯酸(AA)在浓度足够高时形成胆甾型液品,并在一定的浓度范围内呈现胆甾型液晶特有的选择反射一定波长可见光的特性。自由基引发AA聚合得到ECEC/聚丙烯酸(PAA)复合物。复合物的形态结构与聚合前的溶液状态有关。在从各向同性溶液聚合得到的复合物中,ECEC以无定形棒状聚集态存在;而从各向异性溶液聚合得引的复合物部分保留了聚合前的液晶结构,其中ECEG分子取向排列形成ECEC片层状相区,并在更高层次上ECEC片层与PAA片层交替重叠形成一种“千层饼”结构。复合物中液晶结构的保持是物理缠结和化学交联的结果。

THE MORPHOLOGY AND STRUCTURE OF ETHYLCYANOETHYL CELLULOSE/POLYACRYLIC ACID COMPOSITE

Ethylcyanoethyl cellulose(ECEC)/acrylic acid(AA)could form cholesteric liquid crystal when the concentration was high enough,and was iridescent at concentrations between 40—50wt％. ECEC/Polyacrylic acid (PAA) composites could be obtained by radical polymerization of AA in the solutions. They had different morphology depending on the characteristic of solution before polymerization. In the composite produced from the isotropic solution, rod-like amorphous ECEC phase was formed, while in the composite produced from the anisotropic solution, the liquid crystalic structure was partly retained,and the ECEC moleculars arranged orderly in lamellar phase.The retertion of the liquis crystalic structure was attributable to both the intertwing of the polymerizing monomer with ECEC and the cross-linking via reaction with ECEC.