Ionic liquid pretreatment of bagasse improves mechanical property of bagasse/polypropylene composites

For preparation of wood-plastic composites, pretreatment of lignocellulosic material is important to increase compatibility between matrix polymers and lignocellulosic fillers. In this study, choline acetate (ChOAc, a cholinium ionic liquid) assisted pretreatment of bagasse powder could improve properties of chemically modified bagasse/polypropylene composites. The composites had fewer voids derived from vascular bundles of the bagasse tissue when using ChOAc-pretreated bagasse powder compared with the case when using untreated bagasse powder. The tensile strength of the composites was 20 MPa, 35 MPa, and 40 MPa in the cases of polypropylene only, untreated bagasse powder, and ChOAc-pretreated bagasse powder, respectively. The elastic modulus was 0.7 GPa, 2.0 GPa, and 2.6 GPa in the case of polypropylene only, the case using untreated bagasse powder, and the case using ChOAc-pretreated bagasse powder, respectively. Thus, ChOAc pretreatment of bagasse powder could enhance the blending and the tensile property of propionylated bagasse/polypropylene composites compared with those of the composites made using untreated bagasse powder.