Effect of titanate coupling agents on mechanical properties of mica‐filled polypropylene

Abstract

Abstract The application of titanate coupling agents for the surface modification of mica filler and its reinforcement in polypropylene (PP) has been directed towards improvement in mechanical properties. Four titanate coupling agents, namely neoalkoxy tri(dioctylpyrophosphato) titanate (C 1 ), neoalkoxy trineodecanoyl titanate (C 2 ); bis‐(acetylacetonato)distearato titanate (C 3 ), and bis‐(acetylacetonato)dipalmitato titanate (C 4 ) were used in the present investigation. Mica powder (10 μm particle size) was coated with these coupling agents of varying concentration (0.5 to 1 % on the weight of filler) and then blended with polypropylene powder of 10 melt flow index. The mica (10 to 50 wt. %) filled polypropylene samples with and without coupling agents, were injection molded and the mechanical properties of the specimens tested. There is an improvement in the tensile, flexural, and impact strength of PP/mica samples coupled with titanates. The best performance in terms of yield stress and flexural strength was observed in PP/mica samples having 0.7% C 1 , titanate coupling agent. The fracture behavior of mica filled PP has also been studied using a scanning electron microscope.