Karboksimetilasi Selulosa Mikrofibril Guna Meningkatkan Sifat Termal dan Mekanik Komposit Poliasam Laktat

Abstract

Composite of polylactic acid (PLA) reinforced with microfibrillated cellulose (MFC) could replace petroleum-based plastics for automotives and electronics purposes. Unfortunately, the hydrophilicity of nanofibers make it difficult to attain good dispersion in a hydrophobic PLA matrix. Therefore, MFC was modified to carboxymethyl-MFC (CM-MFC) with DS 0.1 and 0.4 to enhance dispersion of nanofibers in a PLA matrix, thus improve the thermal and mechanical properties of the PLA composite. CM-MFC with DS 0.1 and 0.4 were obtained under reaction conditions of water and isopropanol (1:1 and 0:1). PLA composites were prepared using organic solvent, followed by kneading and hot pressing. The thermal and mechanical properties of PLA composites showed that the carboxymethylated MFC in the solvent accelerated the crystallization of PLA and improved the modulus of elasticity, tensile strength, and maximum strain by 0.4 GPa, 9 MPa, and 1%, respectively, at a fiber content of 10 (b/b)%. Based on these information, the dispersion and properties of PLA/MFC composites were enhanced using carboxymethylation at DS 0.1.