渗透压一点法测定聚合物分子量

渗透压一点法测定聚合物分子量 ONE POINT METHOD FOR OSMOTIC DITERMINATION OF MOLECULAR WEIGHT FOR POLYMER 张俐娜 Zhang Lina Zhou Guangying Tian Li first-author 周光应 田黎 用动态渗透压法和粘度法得到聚[4-（4′-八甲基四硅氧基）二苯醚]和聚氯乙烯各分级试样的第二维利系数A 2 、数均分子量 n 、特性粘数[η]及斜率常数β.结果表明,在四氢呋喃中25℃时,聚[4-（4′-八甲基四硅氧基）二苯醚] 和聚氯乙烯的A 2 ～ n 关系式及A 2 n /[η]平均值分别为:A 2 =2.8×10 -2 n -0.27 ;1.2及A 2 :8.8×10 -2 n -0.38 ;1.1. 基于Yamakawa和Gundiah的工作,由我们的渗透压实验数据提出经验式: A 2 M n /[η]=β/0.1157,它可用于近似计算A 2 ,并且由此得到一点法计算数均分子量的经验方程: M m =RT/（π/c）（1+4.32c·β·[η]） 2 这里c—浓度,π—渗透压,R—气体常数,T—绝对温度。用实验和文献数据按一点法与常规法计算的结果基本一致。 The osmotic second virial coefficient A 2 , the number average molecular weight n , the intrinsic viscosity[η] and the slope constant β have been obtained for the fractions of poly [4-（4’-octamethyltetrasiloxanyl）-diphynylether] and Polyvinyl chloride by the dynamic osmornetry and viscosimetry. The rcsults show that A 2 ～ n relationships and average values of （A 2 n ）/[η] for poly [4-（4’-octamethyltetrasiloxanyl）-diphynylether] and polyvinyl chloride in THF at 25℃ are A 2 =2.8×10 -2 M n -0.27 ; 1.2 and A 2 =8.8×10 -2 n -0.38 ; 1.1 respectively. Based on the work of Yamakawa and Gundiah and the data abtained from our osmotic experiment, we have proposed the empirical expression for evaluation of A2: （A 2 M n ）/[η]=β/（0.1157） and one-point method equation for estimation of where c is the concentration, π is the osmotic pressure, R is the gas constant and T the absolute temperature. The results calculated in terms of one-point method and ordinary method agreed well either with experimental data and literature data. 1981-03-01 2021-04-01 3