摘要
本文采用十二种已知分子量的单分散聚苯乙烯(PS)为标准试样,在流动相N,N-二甲基甲酰胺(DMF)中加入低分子量电解质磷酸(H3PO4)来屏蔽聚酰胺酸的聚电解质效应。以七个系列不同结构、不同特性粘度的聚酰胺酸进行凝胶渗透色谱(GPC)淋洗试验。通过凝胶渗透色谱(GPC)法来测定聚酰亚胺的前体——聚酰胺酸(PAA)的Mark—Houwink方程参数K和α。本文根据Mark—Houwink方程的对数形式lg[η]=lgK+αlgM,以聚酰胺酸的lg[η]分别对lgMn、lgMw作图(称为双对数图),由直线的斜率和截距得到了Mark—Houwink方程参数K1、α1和K2、α2,来建立相应的方程。这样由聚酰胺酸在DMF溶液中的特性粘度[η],就可求得相应的数均分子量Mn和重均分子量Mw。
Twelve monodisperse polystyrene （PS） with known molecular weight were used as standard sample, and polyelectrolyte effect of poly （amic -acids） was shielded by adding low molecular weight electrolyte phosphoric acid （H3 PO4 ）in mobile phase N, N -dimethyl formamide（DMF） in this study. Seven series of poly （amic -acids） with different molecular structure and intrinsic viscosity were tested by gel permeation chromatography （GPC）. The constants of K and α in the Mark - Houwink equation of poly （ amic - acids）, the precursor of polyimide, were determined by GPC. According to logarithm form of Mark - Houwink equation, lg[η] =lgK ＋ αlgM, double logarithm plot was obtained by ploting lg[η] vs lg Mn and Ig Mw. The constants of K and α in the Mark - Houwink equation, which were determined by measurements of slope and intercepted length of beelines, were used to establish corresponding equation in this study. According to intrinsic viscosity of poly （amic -acids） in DMF, number average and weight average molecular weight can be calculated.
出处
《南昌航空大学学报（自然科学版）》
CAS
2008年第3期49-56,共8页
Journal of Nanchang Hangkong University(Natural Sciences)
