Development of composite membrane of crystalline polymers

研究了制备复合膜的重要特点之一，聚2-乙烯基吡啶晶体的生长机理。采用正醇和碳氢化合物的不同组合作为混合溶剂，考察了沉淀行为。在0.03% P2VP溶液中，考察了聚合物溶液的混浊温度随1-辛醇浓度的变化规律。溶剂中1-辛醇浓度越高，混浊温度越高。用酒精和碳氢化合物的其他组合进行结晶溶剂的测量，得到了溶剂中混浊温度与酒精浓度之间的相同关系。结果表明，聚合物浓度越低，云雾温度越低。聚合物浓度与混浊温度的关系表明该体系具有较低的临界溶液温度（LCST）行为。这一关系也表明该相分离不是液-液相分离，而是固-液相分离。这种固液分离与溶液生长晶体的形态不是球形而是片状相一致。界面扰动是制备两种结晶聚合物复合膜需要解决的问题。

One of the important feature of preparing the composite film, growth mechanism of poly(2-vinyl pyridine) crystal was eluscidated. Precipitation behavior was examined by using various combinations of n-alcohols and hydrocarbons as the mixed solvent. The clouding temperature of polymer solution was examinedas a function of concentration of 1-octanol in the 0.03% P2VP solution in the mixture of 1-octanol and decalin. In higher concentration of 1-octanol in the solvent clouding temperature became higher. Measurement using other combination of alcohol and hydrocarbon for crystallizing solvents resulted in same relationship between clouding temperature and alcohol concentration in the solvent. The results show that the polymer concentration become lower, clouding temperature decrease. This relationship between polymer concentration and clouding temperature indicated that this system showed lower critical solution temperature (LCST) behavior. And this relationship also indicated that this phase separation was not liquid-liquid phase separation but solid-liquid phase separation. This solid-liquid phase separation corresponds to the fact that the morphology of the solution-grown crystal was not spherical shape but platelet. Disturbance of the interface is left for the problem to be solved for preparation of the composite film of two crystalline polymers,