Synthesis and Characterization on Biodegradable Resin of polylactic acid composite Derivatives and Carboxymethyl Cellulose

Carboxymethyl cellulose(CMC) with a degree of substitution(DS) of 2.5 and polylactic acid (PLLA) were plasticized by melt extrusion using triacetin. The resulting thermoplastic materials were then prepared and characterized by their tensile strength and differential scanning calorimetry(DSC). Thermal analysis revealed the invariability of the PLLA glass transition temperature in all blends, indicating that the compounds were immiscible. Grafted lactide to CMC copolymers were prepared by reactive melt processing using CMC with different degree of substitution. The compatibility of the blends was investigated by scanning electron microscopy(SEM). Results showed that blend compatibility was improved evidencing the best performance of grafted copolymers with long grafted chains as compatibilizer of CMC/PLLA. Finally, compatibilized compositions with enhanced ultimate elongation were achieved by using plasticized PLLA instead of neat PLLA. Biopolymers including polysaccharides and proteins have beenincreasingly paid attention in food packaging application due totheir low cost and good film forming properties.