The Effect of Filler Loading on Tensile and Morphological Properties of Polylactic Acid (PLA)/ Thermoplastic Corn Starch (TPCS)/ Peanut Shell Powder (PSP) Biocomposites

A new route to prepare poly(lactic acid)(PLA)/thermoplastic starch (TPCS) blends is described in this study. Peanut shell powder (PSP) was used as natural filler and the effect of PSP loading were investigated. TPCS were prepared by mixing the corn starch (65 wt.%) and glycerol (35 wt.%) in a high speed mixer. PLA/TPCS blend ratio were maintained at 80 wt.% of PLA and 20 wt.% of TPCS. PLA/TPCS/PSP composites with various loading of PSP (10, 20, 30 and 40 wt.%) were prepared by using an internal mixer at 180 degrees C. Results indicated that the incorporation of PSP increased the tensile strength of PLA/TPCS/PSP biocomposites until reaching the maximum at 30 wt.% of PSP loading. The tensile strength decreases as more PSP added into the matrix. The elongation at break of PLA/TPCS/PSP biocomposites decreased gradually as more addition of PSP loading. The tensile modulus of PLA/TPCS/PSP composites increases as PSP loading increased. The scanning electron micrograph (SEM) of the tensile fracture surfaces of the PLA/TPCS/PSP composites revealed that the interfacial adhesion between PLA, TPCS and PSP improved at 30 wt.% of PSP loading.