Yield behavior of polypropylene filled with CaC03 and Mg(OH)2. I: “Zero” interfacial adhesion

Abstract The composition dependence of tensile yield stress (σ yc ), and the effects of filler particle shape and surface treatment were investigated for polypropylene (PP) filled with CaCO 3 or with Mg(OH) 2 . Poor adhesion between PP and CaCO 3 accounted for a decrease of σ yc with increasing σ f . In spite of the poor adhesion between PP and Mg(OH) 2 , σ yc either slowly decreased with increasing V f or remained constant up to V f = 0.25. Surface treatment of the fillers facilitated better dispersion in PP. On the other hand, σ yc was reduced due to the lower thermodynamic work of adhesion ( W A ). The semiempirical one‐parameter equation proposed by Turczanyi, Pukanszky, and Tüdüs (TPT) was considered plausible and was employed in the study of the effects of matrix‐filler interaction.