Interphase layer formation in isotactic polypropylene/ethylene–propylene rubber blends

Autor: Baranov, Andrey O., Erina, Nataliya A., Kuptsov, Sergey A., Medintseva, Tatiyana I., Prut, Eduard V.
Zdroj: Journal of Applied Polymer Science; 5 July 2003, Vol. 89 Issue: 1 p249-257, 9p
Abstrakt: The influence of the interphase layer, formed by the introduction of an oil in ethylene–propylene rubber (EPR), on the structure and properties of isotactic polypropylene (iPP)/EPR blends was studied. The dispersity of the rubber phase in the iPP matrix did not depend on presence of oil. The melting temperature of iPP decreased with increasing content of oil-extended EPR, and it did not change if the oil was absent. The compatibility parameter was determined from the dependency of the iPP melting point on the rubber content with the Nishi–Wang equation. A negative value of the parameter indicated a limited compatibility of iPP with oil-extended EPR. The latter also reduced the temperature and heat of crystallization of iPP. The mechanical properties of iPP/EPR blends were investigated as functions of temperature and elongation rate. It appeared that elastic modulus and yield stress of the blends linearly depended on the logarithm of the elongation rate. Activation volumes, calculated with the Eyring equation, increased with increasing content of elastomer; moreover, this increase was more pronounced for the oil-extended elastomer. It is suggested that the oil influenced the structure of the interphase layer and, accordingly, the characteristics of the iPP/EPR blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 249–257, 2003
Databáze: Supplemental Index
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