Enzymatic modification of jute fabrics for enhancing the reinforcement in jute/PP composites

In this work, laccase was employed to improve the properties of lignocellulosic jute fabrics and then the modified jute was used as the fiber reinforcement of polypropylene (PP) matrix composites to improve its reinforcing effect on the polymer resins and obtain composite materials with better performance. The decrease in the -C-O-H component and the increase in the -C-O-C component on the surface of laccase-treated jute fabrics suggested that phenolic hydroxyl groups of lignins on the jute fiber surface were oxidized by laccase and the produced phenoxyl radicals were coupled to form ether structures. The laccase-treated jute fiber surface became smooth with lignins attached tightly. Moreover, the surface hydrophobicity and tensile properties of the jute fabrics were increased via the laccase-mediated reactions of lignins. PP composites reinforced by the laccase-treated jute fabrics showed higher breaking strength, storage modulus, and melting temperature than the control. The fracture surface of the laccase-treated jute fabric/PP composites was neat and jute fibers on the section surface were surrounded by PP resins closely, which indicated better interfacial adhesion between the modified jute reinforcement and PP matrix.