Evaluation of Coupling Agents in Poly(propylene)/Fly Ash Composites: Effect on Processing and Mechanical Properties

Abstract

Abstract Composites containing 50 wt.‐% fly ash in a PP homopolymer were prepared via batch mixing and compression moulding. The following coupling agents were evaluated: Lubrizol Solplus C800, N,N ′ ‐ (1,3‐phenylene)dimaleimide, γ‐methacryloxypropyltrimethoxysilane and maleic‐anhydride‐grafted PP. At the filler level investigated, C800 gave the best balance of composite strength and toughness. In the latter case filler‐matrix adhesion appeared weaker relative to γ‐MPS, BMI and m‐PP, all of which gave excessively strong filler‐matrix adhesion leading to a reduction in composite toughness. The unexpected weakness of the C800/fly ash interaction may be related to removal of surface calcium ions from the fly ash via reaction of a single calcium ion with two C800 molecules. magnified image