Effect of the aerosil surface on its interaction energy with polyvinylchloride and on mechanical properties

Abstract

The heats of interaction between PVC and Aerosils having various types of surface have been determined and compared with the mechanical properties of compositions based on them. Modified Aerosils interact less intesively with PVC than does the unmodified Aerosil, a fact that is related to differences in the heats of wetting by the plasticizer. As the interphase interaction becomes stronger in the series of fillers studied, the dynamic and equilibrium moduli of elasticity increase whereas the peel strength and rupture strength decrease. Clearly, as the interaction between PVC and the filler surface increases, the rigidity of the specimens rises and the thickness of the boundary layer increases, which leads, in the interphase boundary, to a reduction in the rate of relaxation of the stresses arising during the specimens' deformation and favours the stripping of the PVC from the filler surface at lower stresses.