Bio-based green composites with high performance from poly(lactic acid) and surface-modified microcrystalline cellulose
writer：Lin Xiao, Yiyong Mai, Feng He, Longjiang Yu, Limin Zhang, Huiru Tang and Guang Yang *
keywords：cellulose, green composites
source：期刊
specific source：JMC，2012，22, 15732–15739
Issue time：2012年
ABSTRACT: Bio-based green composites with high performance were prepared from poly(lactic acid) (PLA) and microcrystalline cellulose (MC) fibers grafted with L-lactic acid oligomers (g-MC). The chemical structure of g-MC was characterized by FTIR and NMR methods, which indicate that L-lactic acid oligomers were successfully grafted onto microcrystalline cellulose. The grafting percentage of L-lactic acid oligomers is ca. 3%, and the average degree of polymerization of grafted L-lactic acid oligomers is ca. 10. The compatibility between PLA and MC is significantly improved by the grafting modification. SEM micrographs and sample transparency show that the g-MC has a good dispersion and homogeneity in the g-MC/PLA composites. DSC studies indicate that the crystallinity of PLA is enhanced by the g-MC existed in the composites. Due to the improved compatibility between g-MC and PLA, the g-MC/PLA composites exhibit better mechanical properties than pure PLA, with a high tensile strength of 70 MPa as well as a higher elongation at break. The enhanced properties along with the excellent biocompatibility and degradability would offer the biobased composites potential applications in biomedical fields and the packaging industry.