Abstract

Cellulose was grafted with Poly(L-lactide) (PLLA) to synthesize cellulose-g-PLLA in this study, which improved the water repellency of woody thin boards made of cellulose and lignin, prepared by a compression molding. It was clarified, from the diagram study of ternary cellulose/lignin/water phase system, that the content of cellulose-g-PLLA was crucial to form WTBs. The best performance of water repellency for WTBs was 126deg of the contact angle (30 % content of cellulose-g-PLLA), as compared with 50deg for bare WTB. This was likely to result from the hydrophobicity of PLLA modified at the surface of cellulose particles. Moreover, the stability of WTBs for six years was improved by celluloseg- PLLA. The improved stability can be explained by an entanglements between PLLA polymer chains or between PLLA and lignin.

Keywords: Cellulose-g-PLLA; Water repellency; Long-term stability; Woody thin board