Rheological and structural assessments of polymer blends in phase inversion conditions

Abstract

The aim of the work was to estimate the range of phase inversion occurring dependently on the composition of the blends of two types of isotactic polypropylene with polycarbonate [PP(S901)/PC and PP(PEL)/PC]. The study consists of the assessment of Theological properties (Fig. 2 and 3) and observations of the structure by polarized light optical microscopy (Fig. 4 and 5) as well as scanning electron microscopy (Fig. 6 and 7). The results of the structure investigations confirmed the statement that observed abrupt changes of viscosity were caused by phase inversion. The phase inversion consists here in both PP and PC functioning either as a matrix or a dispersed phase, dependently on the composition. The effect of amorphous PC phase on i-PP crystallization has been also discussed. Characteristic transition illustrating the phase inversion in the range of 80 - 85 wt. % of PC in PP(S901)/PC blend and in the range of 85 - 90 wt. % of PC in PP(PEL)/PC blend was determined. A correlation between the point of phase inversion occurring, determined experimentally with that one calculated on the basis of mathematical models, taken from the literature (Table 1), is presented.