Kinetic considerations on the mechanical behaviour of polypropylene + wood flour and polypropylene + sisal fibre blends

Abstract

This work is aimed at analyzing by means of simple mathematical models the effect of different integral doses of γ-irradiation on the mechanical properties and concentration of radicals of the blends of polypropylene (PP) + wood flour and PP + sisal fibre. The analysis of the results permits inferring that the kinetic behaviour of the mechanical properties and the concentration of radicals at low integral doses (≤10 KGy) are indicative of a complex degradation process, implying the possibility of cross-linking and chain scission reactions both in the polymer as well as in the filler. Consequently, it can be concluded that cross-linking reactions are predominant. The behaviour observed at higher irradiation doses means that both reactions (cross-linking and chain scission) occur, the breaking reactions being the prevailing ones. This study of the kinetic analysis of the tensile properties is based on the behaviour detected for the melt-flow index.