Effect of interfacial interactions on the dispersity of binary blends of incompatible polymers

The effect of interfacial interactions on the size of particles in a disper se phase formed upon blending isoviscous incompatible elastomers was studie d. The experiments were performed in a series of five 20 : 80 blends compri sing an EPDM matrix with various elastomers as the disperse phase. Viscosit ies of the blend components were leveled by mastication of a more viscous p olymer in a roll mill, so that a difference between the viscosities of phas es did not exceed 20%. Since no published data on the interfacial tensions of the polymers studied were found, the interphase interactions in the syst em were characterized by differences of the surface tensions or cohesive en ergy densities of the components. It was established that the size of the d isperse phase particles in the blends of isoviscous polymers decreases with the difference of the surface tensions or cohesive energy densities of the blend components. Problems related to the experimental investigation of in terfacial effects accompanying blending of the polymer melts are discussed.