Preparation of high performance biobased composites from poly(lactic acid) and microcrystalline cellulose

The high performance biobased composites were prepared from poly (lactic acid) (PLA) and microcrystalline cellulose (MC) fibers by graft modification. The morphology, mechanical and thermodynamic properties of the composites were investigated. Fourier transform infrared spectroscopy (FTIR) showed that a kind of grafted microcrystalline cellulose (g-MC) had been successfully synthesized by lactic acid modification. Compared to neat resin, the tensile strength of the composites is significantly higher, and some of the composites even have a perfect breaking elongation rate. This is due to the cellulose fibers that added to the PLA matrix may act as reinforcements. Furthermore, compared to the PLA/MC composites, the PLA/ g-MC composites have a good appearance shape and light transmittance, demonstrated that the g-MC had much better dispersion and homogeneity in the composites. Differential scanning calorimetry(DSC) showed that the glass transition temperature (T-g) and the melting point (T-m) of the PLA/ g-MC composites decrease, while the crystallization temperature (T-c) of the PLA matrix increases, which indicated that the presence of g-MC improves the crystallization behaviors of PLA.