Bio-composites of poly(lactic acid) and poly(ethylene oxide) reinforced with wooden cellulose fibers.

Herein, we report the toughening of biodegradable, bio-based polylactic acid (PLA) using eco-friendly poly(ethylene oxide) (PEO), which was reinforced with wood-based cellulose fibers (CFs) using the melt blending method. A silane coupling agent KH792 (N-2-aminoethyl-3-aminopropyltrimethoxysilane) was used to treat the CFs to enhance the interfacial adhesion and compatibility of the prepared composites. Theoretical studies indicated that the silanized fiber CF-K2 exhibited better compatibility in the composites than the unmodified CFs. Morphological observations confirmed the enhanced adhesion between CF-K2 and the matrix in the PLA/PEO/CF-K2 composites. Crystallization characterizations showed that CFs effectively increased the crystallinity of the composites via their strong nucleating role, whereas CF-K2 slightly impeded the crystallization but improved the hydrophobicity of the composites. The melt viscosity and storage modulus of PLA/PEO/CF-K2 composites were higher than those of the unmodified composites. However, CF-K2 reduced the thermostability of the composites. The tensile properties of PLA/PEO/CF-K2 composites were better than those of PLA/PEO/CF composites. The PLA/PEO/CF-K2 (79.2/19.8/1) composite exhibited an elongation at break of 335%, which was ~40-fold higher than that of pure PLA. Owing to considerable mechanical and rheological properties of CF-K2 composites, these bio-composites show potential applications in packaging, furniture, construction and other fields.