Reinforcing Mechanical, Water Absorption and Barrier Properties of Poly(Lactic Acid) Composites with Kenaf-Derived Cellulose of Thermally-Grafted Aminosilane

The effects of filling poly(lactic acid) (pla) composites with cellulose thermally-grafted with hydrolysed 3-aminopropyltriethoxysilane (aps) were investigated. composites containing 30 wt% of kenaf-derived cellulose (c) and silane-grafted cellulose (sgc) were melt-blended into a pla matrix before being hot-pressed into 0.3 mm sheets. the tensile strength of neat pla was 47 mpa. with addition of c and sgc,the tensile strength was improved by 13% and 23%,respectively. the tensile modulus was approximately doubled for both of the composites. pla/c and pla/sgc composites remained brittle with marginally lowered elongation at break. the addition of c and sgc significantly increased the oxygen barrier of pla with the reduction of oxygen transmission rate (otr) of pla at 76.6 cc/m^2/day to 42.2 cc/m^2/day and 40.3 cc/m2/day,respectively. this was due to the tortuous path created and crystallites induced by the fillers. the water vapour transmission rate (wvtr) for pla,pla/c and pla/sgc was in the range of 21-23 g/m^2/ day. from the water absorption test,pla/sgc reported slightly better water resistance as compared to pla/c. the reinforcing results from these bio-based materials may suggest contribution towards packaging oxygen and moisture sensitive food.