Characterization of interfacial compatibility of polylactic acid and bamboo flour (PLA/BF) in biocomposites

The applicability of bamboo flour (BF) blended with polylactic acid (PLA) to improve the properties of PLA for widespread use as an environmentally friendly, biodegradable polymer is limited by the poor compatibility of these materials. Therefore, as a potential compatibilizer for PLA/BF composites, PLA-g-glycidyl methacrylate (GMA) was synthesized by grafting GMA onto PLA using benzoyl peroxide and tert-butyl peroxy benzoate as initiators. GMA grafting onto PLA was confirmed by infrared testing and elemental analysis. Then, PLA/BF biocomposites were prepared by blending PLA (85 wt%) and BF (15 wt%) with different concentrations of PLA-g-GMA. The phase morphology, thermal stability and mechanical properties of the composites prepared with PLA-g-GMA were improved over those of PLA/BF composites without compatibilizer, as characterized by scanning electron microscopy, thermogravimetric analysis and using a universal materials tester, respectively. Specifically, the thermal decomposition temperature, tensile strength and tensile modulus of PLA/BF biocomposites prepared with 15 hpr PLA-g-GMA were increased.