Cellulose esters as compatibilizers in wood/poly(lactic acid) composite

One of the important issues relevant to wood/plastic composite molding is the compatibility between hydrophilic wood and hydrophobic plastic. Polyolefins modified with maleic anhydride, which have been frequently used for wood and polyolefin composites, are not effective for poly(lactic acid) composites. Because compounds with both hydrophilic and hydrophobic groups are potential compatibilizers, cellulose esters of several carboxylic acids, RCOO-cellulose (R = CH₃, C₂H₅, C₃H₇, C₄H₉, C₅H₁₁, C₁₁H₂₃), were synthesized and their effects as compatibilizers of wood/poly(lactic acid) composites (WPLC) were examined in this study. The mechanical properties of WPLC were improved with a small amount of added cellulose esters, especially cellulose butyrate or cellulose valerate. The relevant effect of added cellulose esters on the thermal properties of wood/PLA composite was analyzed by measuring dynamic viscoelasticity. Part of this report was presented at the 56th Annual Meeting of Japan Wood Research Society, Akita, August 2006 and the 9th International Conference on Frontiers of Polymers and Advanced Materials, Cracow, Poland, July, 2007