平菇多糖稀溶液行为的研究

STUDIES ON THE DILUTE SOLUTION BEHAVIOR OF POLYSACCHARIDE OF PLEURATU OSTRETUS

干菇多糖属生物高分子,文章对平菇多糖稀溶液性质进行了研究。实验系采用Elias浊点滴定法测定平菇多糖溶液的θ组成,用快速动态膜渗透计和粘度法测定平菇多糖的数均分子量、维利系数与分子链的构型参数。探讨其在θ条件下的分子形态及用Tung函数法等处理分级数据,从而获得平菇多糖的分子量分布。

The polysaccharide of pleuratu ostreatus was fractionated by repeated precipitation method. Modified Elias cloud-point titration method with an UV detecter was used to determine the cloud-point. It was found that water/acetone (83. 5:16. 5 by volume)is a θ-solvent for the polymer at 25℃. Number average molecular weights of allsamples fractionated were characterized by rapid dynamic membrane osmometry andviscometry. The second virial coefficient A_2 decreases as the molecular weight in-creases. The relationship is A_2=2 slope (M_nRT)^(-1/2). The intrinsic viscosities were determined by capillary viscometry in θ-solvent.Thus and thus a mondispersed [η]～M relationship has been obtained: [η]_θ=0. 124M^(0.513)The unperturbed dimension h_θ~3 was found to be [η]_θM_n/0.284×10^(24). It shows that thechain of polymer in θ-solvent is more flexible. Determination of the distribution curve by means of fractional precipitation. Thedistribution-curve of integral and differential is obtained.