Stearic acid as coupling agent in fly ash reinforced recycled polypropylene matrix composites: Structural, mechanical, and thermal characterizations

Abstract

ABSTRACTTwo industrial wastes, fly ash (FA) and recycled polypropylene (RPP) were used to prepare a value‐added, sustainable, low cost composite material. Improving the interfacial interaction between the hydrophobic RPP matrix and the hydrophilic FA particles is important to get a good combination of properties. In order to tailor the interface, stearic acid was used as the coupling agent. The FA particles were coated with a saturated fatty acid, stearic acid (SA), in different weight % like 1, 2, 3, and 5. The SA coated fly ash particles were incorporated as filler in RPP matrix composites by melt mixing in 1 : 1 weight ratio. The composites were tested for their flexural properties, impact behavior, dynamic mechanical properties, fracture surface analysis, X‐ray diffraction (XRD) study, and differential scanning calorimetry (DSC). An increase in flexural modulus and impact strength was observed in the stearic acid coated FA/RPP composites. In 1 wt % SA treated FA/RPP (RFASA1) composites, a significant increase in glass transition temperature was observed along with an increase in crystallinity. A green, renewable, inexpensive chemical like stearic acid was thus found to be an effective coupling agent in fabrication of a composite with 50 wt % filler loading. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1996–2004, 2013