Yield behavior of PP/CaC03 and PP/Mg(OH)2 composites. II: Enhanced interfacial adhesion

Effects of the variation of adhesion strength σA on the tensile yield behavior of particulate filled polypropylene (PP) were investigated. To enhance adhesion of PP toward calcium carbonate (CaCO3) and magnesium hydroxide (Mg(OH)2), maleated PP (MPP) was added to PP in various ratios. σA varied from 10‐46 MPa. σA calculated from the Leidner‐Woodhams model are in good agreement with SEM micrographs of the composite fracture surfaces. Dependences σyc vs. σA, at constant Vf = 0.18, were investigated and analyzed in terms of existing models. Using the Turczanyi, Pukanszky, Tüdös model (TPT) for the PP/CaCO3 composite, an effective interlayer “thickness” (teff) and the yield stress of the immobilized PP (σyi) were calculated. Both teff and σyi increased with enhancing of the adhesion.