Effect of Boron Compounds on Physical, Mechanical, and Fire Properties of Injection molded Wood Plastic Composites

摘要

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites (WPCs) incorporated with different levels of boron compounds, borax/boric acid (BX/BA) (0.5:0.5 wt %) and zinc borate (ZB) (4, 8, or 12 wt %) were investigated. The effect of the coupling agent loading (2, 4, or 6 wt %), maleic anhydride-grafted PP (MAPP), on the properties of the WPCs was also investigated. Incorporation of the fire retardants (FRs) into the WPCs decreased the physical and mechanical properties as compared to the WPCs without FR. The FR treatments had little impact on the fire performance of the WPCs in the cone calorimeter tests. The WPCs containing the ZB showed better water resistance and strength values in the bending, tensile, and izod impact than the WPCs containing the BX/BA. The SEM-EDS micrographs revealed that the outer surface of the wood fibers was surrounded by some crystalline deposits of the FRs. This resulted in the poor compatibility between the wood and polymer matrix in the WPCs containing the FRs. With the addition of the MAPP up to 4 wt %, the water resistance and mechanical properties of the WPCs containing FRs up to 8 wt % improved. But the further increasing of the MAPP (6 wt %) did not improve the properties of the WPCs containing FR (12 wt %).