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1.聚甲基丙烯酸甲酯-丙酮-甲醇体系的两次分相实验用θ-溶剂中的沉降速度法测定分相前试样和浓相的分子量分布曲线,得到高分子在浓稀相重量分配的分子量依赖关系 f″_j=Qe~(σM_j) 证实Flory的溶度函数形式与实际相符,并适用于三元体系的相分离,但Q值与两相体积比R值并不相同。 2.再分级使级分的分子量分布宽度随再分级次数的增加而减小,通常认为到第三次再分级其效果已不显著并不确实。 3.建议一种用两次相分离实验和五次精密的特性粘数测定,结合从[η]_(■)和[η]_θ值估计分子量分布宽度,得出分子量分布曲线的简便近似力法。
1. Polymethacrylic acid methyl ester - acetone - methanol two-phase separation experiment with θ-solvent sedimentation velocity method before the phase separation of the sample and the concentration of the molecular weight distribution curve to give the polymer in the dilute phase weight The distribution of the molecular weight dependence f "_j = Qe ~ (σM_j) confirmed that Flory’s solubility function is consistent with the actual form, and is suitable for the ternary system phase separation, but the Q value and the two-phase volume ratio R value is not the same. Reclassification makes the molecular weight distribution of the fraction decreases with the increase of the number of re-classification, it is generally considered that the effect of the third re-classification has been insignificant and not valid.3.It is suggested that a two-phase separation experiment and five The determination of intrinsic viscosity was carried out with the help of a simple approximation method for estimating the molecular weight distribution curve by estimating the width of molecular weight distribution from [η] _ (■) and [η] _θ values.