PRECISION MEASUREMENTS OF OSMOTIC PRESSURE IN CONCENTRATED POLYMER SOLUTIONS
PRECISION MEASUREMENTS OF OSMOTIC PRESSURE IN CONCENTRATED POLYMER SOLUTIONS
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DOI：
10.1016/0014-3057(71)90035-8
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发表时间：
1971-01-01
影响因子：
6
通讯作者：
VINK, H
中科院分区：
文献类型：
--
作者：
VINK, H
用几种聚合物(葡聚糖、羟乙基纤维素、聚乙烯吡咯烷酮和聚环氧乙烷)在水溶液中进行了渗透压的精确测量。在较宽的浓度范围内(最高可达0.2g/cm3)建立了渗透压的浓度依赖关系；研究了样品的相对分子质量和相对分子质量不均一性的影响。在所研究的所有情况中，都发现在渗透压的维里展开中，第四和更高的维里系数在实验误差范围内为零。研究了渗透压对温度的依赖关系，测定了溶剂的偏摩尔热和混合熵。对于所研究的溶液，混合热和混合熵总体上是密切相关的。混合热均为负，在葡聚糖溶液中为正混合熵，在其他聚合物溶液中为负混合熵。
Precision measurements of osmotic pressure have been carried out with several polymers (dextran, hydroxyethyl cellulose, polyvinylpyrrolidone and polyethlene oxide) in aqueous solutions. The concentration dependence of the osmotic pressure over a wide range of concentrations (up to 0·2 g/cm3) was established; the influence of the molecular weight and the molecular weight heterogeneity of the samples was studied. In all cases investigated, it was found that in the virial expansion of the osmotic pressure the fourth and higher virial coefficients were zero within experimental error. The temperature dependence of the osmotic pressure was also investigated and the partial molar heats and entropies of mixing for the solvent were determined. For the solutions investigated, the heats and entropies of mixing were in general closely correlated. The heats of mixing were all negative, whereas the entropy of mixing was positive in dextran solutions and negative in solutions of the other polymers.