Effect of surface treatments of banana fiber on mechanical, thermal, and biodegradability properties of PLA/banana fiber biocomposites

Poly lactic acid (PLA)/Banana fiber (BF) biocomposites were fabricated employing melt blending technique followed by compression molding. BF were surface‐treated by NaOH and various silanes viz. 3‐aminopropyltriethoxysilane (APS) and bis‐(3‐triethoxy silyl propyl) tetrasulfane (Si69) to improve the compatibility of the fibers within the matrix polymer. Mechanical tests revealed an increase of tensile strength to the tune 136% and impact strength to 49% as compared with the untreated biocomposite. Thermal properties of the composites have been evaluated using DSC and TGA. DSC thermograms revealed an increase in the melting transitions thus revealing effective fiber/matrix interface. The thermal stability in the biocomposites also increased in case of banana fiber treated with Si69. Viscoelastic measurements using DMA confirmed an increase of storage modulus and low damping values in the silane treated biocomposites. Biodegradation studies in the biocomposites have been investigated in B. cepacia medium through morphological and weight loss studies. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers