Determination of filler content in rice husk ash and wood-based composites by thermogravimetric analysis

Three new types of fillers for polypropylene are investigated. The first two were derived from burnt rice husk ash (RHA), whereas the third, a wood‐based filler, was processed from oil palm trunk. One important characterization of the composites involves the checking for the actual filler content and filler distribution within the matrix. An analytical technique is described here for computation of the filler content in the composites based on a simple expression derives from thermogravimetric analyses. For filler with volatiles such as the black RHA, the derived expression was pf = 106(rb/mc), and for easily burnt fillers (wood‐based), the expression was pf = 156(md/mc). The technique has shown good agreement and consistency between analyzed and actual filler contents and a uniform filler distribution within the polypropylene matrix. © 1994 John Wiley & Sons, Inc.