Abstract
The purpose of this study was to investigate the effects of phosphoryl triamide treatment on
the flexural properties, internal bond strength, and dimensional stability of woodflour-polypropylene
composites. Factors investigated included 3 woodflour loading levels and 7 fire-retardant
treatments. Results showed that fire-retardant treatments adversely affected the flexural strength,
internal bond strength, and dimensional stability of composite panels at a 100% woodflour loading;
however, all of the measured properties improved at higher polypropylene contents, except for the
flexural stiffness which was unaffected by either factor. Woodflour loading and fire-retardant treatments
collectively and interactively affected the performance of woodflour-polypropylene composites,
with the woodflour content a more-important factor than the fire-retardant type.