Compatibilities and properties of poly lactide/poly (methyl acrylate) grafted chicken feather composite: Effects of graft chain length

Surface modified poly(methyl acrylate) (PMA) grafted chicken feather fiber was applied as a reinforcement for polylactide (PLA)-based composite film. The PMA grafted feather fiber with different PMA lengths were obtained for surface initiated Cu(0)-mediated reversible-deactivation radical polymerization. PLA-based composite films with different unmodified or PMA-grafted chicken feather fiber loading were prepared by solvent casting. Grafting PMA onto feather fiber enhanced interfacial bonding. Cracks and voids between matrix and fiber were eliminated. Thermal stability of these films also improved after introducing PMA. Feather fiber with high graft ratio showed worse dispersity in PLA due to its self-aggregation. The heterogeneous nucleation agent behavior of feather grafted with longer PMA was also suppressed. Tensile tests showed that after modification, tensile strength and modulus was able to increase twice at 20% fiber loading. However, increasing PMA length improved break elongation but strength and modulus would drop slightly. These results indicated that grafting short PMA chain onto feather fiber surface was an effective and optimized method to improve dispersity and mechanical properties especially for higher filler loading.