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首页> 外文期刊>Journal of Applied Polymer Science >Influence of temperature, molecular weight, and molecular weight dispersity on the surface tension of polystyrene, polypropylene, and polyethylene. II. Theoretical
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Influence of temperature, molecular weight, and molecular weight dispersity on the surface tension of polystyrene, polypropylene, and polyethylene. II. Theoretical

机译：温度，分子量和分子量分散度对聚苯乙烯，聚丙烯和聚乙烯的表面张力的影响。二。理论上的

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Experimental data for the surface tension of polystyrenes of different molecular weights (3400-200,000) and different molecular weight dispersities (1-3) and of different polyolefins are compared with the predictions of the Patterson-Rastogi and Dee-Sauer cell theories, which infer the surface tension from pressure-volume-temperature (PVT) data. PVT data for these polymers were obtained from the literature and experimentally and are fitted to the Flory-Orwoll-Vrij equation of state. Both theories predict that the surface tension will decrease linearly with increasing temperature and increase with molecular weight, thereby corroborating the experimental data. However, both theories underestimate the entropy change in the surface formation per unit area at a constant volume for low molecular weight and polydisperse systems and underestimate the effect of molecular weight dispersity on surface tension. Both theories feature two parameters, m and b, that quantify the enthalpic and entropic contributions to surface tension. The theoretical predictions are fitted to the experimental data for monodisperse polystyrene (with a molecular weight above the molecular weight of entanglement), polypropylene, and linear low-density polyethylene to quantify the enthalpic contribution to surface tension. b is then evaluated as a function of molecular weight and molecular weight dispersity and is found to decrease with increasing molecular weight and to increase with increasing molecular weight dispersity, showing that end-group excess at the surface has some effect on surface tension. (C) 2002 John Wiley Sons, Inc. [References: 25]
机译：将不同分子量（3400-200,000）和不同分子量分散度（1-3）以及不同聚烯烃的聚苯乙烯表面张力的实验数据与Patterson-Rastogi和Dee-Sauer细胞理论的预测相比较来自压力-体积-温度（PVT）数据的表面张力。这些聚合物的PVT数据可从文献中获得并通过实验获得，并拟合到Flory-Orwoll-Vrij状态方程。两种理论都预测表面张力会随着温度的升高而线性降低，而随着分子量的增加而升高，从而证实了实验数据。但是，这两种理论都低估了低分子量和多分散体系在恒定体积下单位面积表面形成的熵变化，并低估了分子量分散对表面张力的影响。两种理论都具有两个参数m和b，用于量化焓和熵对表面张力的贡献。理论预测与单分散聚苯乙烯（分子量高于纠缠分子量），聚丙烯和线性低密度聚乙烯的实验数据相符，以量化焓对表面张力的影响。然后将b作为分子量和分子量分散度的函数进行评估，发现b随分子量增加而降低，随分子量分散度增加而增加，表明表面端基过量对表面张力有一定影响。 （C）2002 John Wiley Sons，Inc. [参考：25]

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