Interfacial compatibilization via in-situ polymerization of epoxidized soybean oil for bamboo fibers reinforced poly(lactic acid) biocomposites

A simple, efficient and eco-friendly method was developed for improving the interfacial adhesion of bamboo fibers (BFs) reinforced poly(lactic acid) (PLA) biocomposites. A biobased monomer, i.e., epoxidized soybean oil (ESO), was used to in-situ polymerize at the interface between BFs and PLA matrix for forming a polymerized ESO interfacial layer. FTIR and XPS analyses confirmed that the poly(ESO) layer was covalently bonded with both BFs and PLA matrix, resulting in an enhanced interfacial adhesion of the BF/PLA biocomposites. The flexible poly(ESO) layer contributed to a simultaneous strengthening and toughening effect on the biocomposites, hence significantly increased the tensile strength, tensile modulus, fracture elongation, and storage modulus of the biocomposites. However, the glass transition temperatures, melting temperatures, and cooling crystallization temperatures of the biocomposites were slightly decreased due to the incorporation of ESO.