Lee et al. [6], have reported that the addition of polypropylene grafted with maleic anhydride (MAPP) was able to improve the mechanical properties of wood-plastic composites (WPC). This improvementwas attributed to the increase of compatibility between the wood flour and PP. Hristov and Vasileva[7], and Stark and Rowlands [8], have also found thatMAPPhas a positive effect on the mechanical proper-ties of WPC and can improve the tensile modulus,yield strength and impact strength of the composite.Toro et al. [9] have found that PPgrafted withmonomethyl itaconate (PP-g-MMI) improves theinterfacial adhesion in polypropylene-co-ethylene/RHcomposites.