Mussel-inspired reinforcement of a biodegradable aliphatic polyester with bamboo fibers

Natural fiber-reinforced biocomposites displaying light weight, low thermal conductivity and reduced environmental footprint are increasingly relevant in structural, packaging, cementitious and masonry materials. However, the poor interfacial compatibility between fibers and typical polymers has limited the development of mechanical strength and water resistance. Here, we report a green, facile and effective method inspired by nature to promote interfacial adhesion in biocomposites based on a biodegradable aliphatic polyester (polybutylene succinate, PBS). For this purpose, PBS was reinforced with bamboo fibers modified with (3-aminopropyl) triethoxysilane and polydopamine (PDA). The PDA deposition and covalent adhesion with the fibers were promoted by self-polymerization and Michael addition and/or Schiff based secondary reactions. A distinct improvement in reinforcement was achieved together with gains in performance, including tensile strength (70%), tensile modulus (25%), flexural strength (37%), flexural modulus (24%) and impact strength (63%). The results far exceeded those measured for other fiber-reinforced biocomposites while simultaneously introduced water resistance.