Biocomposites based on poly(lactic acid) matrix and reinforced with natural fiber fabrics: The effect of fiber type and compatibilizer content
Mun Wai Tham, Nurul Fazita Mohammad Rawi, H. P. S. Abdul Khalil, M. Mariatti, Ahmad Rashedi, Mohamad Haafiz Mohamad Kassim
Abstract
Abstract Polylactic acid (PLA) was reinforced with either bamboo or jute fabric to produce 30 wt% composites. However, hydrophobic PLA and hydrophilic natural fiber are incompatible. Hence, maleic anhydride grafted PLA (PLA‐g‐MA) used as compatibilizer. In this study, effect of grafting reactants content, maleic anhydride (MA) and dicumyl peroxide (DCP) on MA grafting degree of PLA‐g‐MA were optimized using Taguchi experimental design. Synthesized PLA‐g‐MA exhibiting highest MA grafting degree used as compatibilizer at 3 wt%, 5 wt%, and 10 wt% for 30 wt% composites. These compatibilized 30 wt% composites were investigated for their water absorption, thermal stability, thermal, mechanical, and dynamic mechanical properties. PLA‐g‐MA addition at 3 wt% onto 30 wt% bamboo/PLA or at 5 wt% onto 30 wt% jute/PLA enhanced their interfacial adhesion, increasing their T g , T m , X c , tensile, flexural, impact and storage modulus but reduced their water absorption, T cc and damping factor. Further PLA‐g‐MA addition above 3 wt% onto 30 wt% bamboo/PLA or above 5 wt% onto 30 wt% jute/PLA adversely affected their water absorption, thermal, mechanical and dynamic mechanical properties. This was attributed to excess uncoupled PLA‐g‐MA acting as plasticizer. Adverse effects also observed for their thermal stability when PLA‐g‐MA was added onto 30 wt% bamboo/PLA or 30 wt% jute/PLA. This was attributed to higher grafting reactant content, MA and less thermally stable PLA‐g‐MA.