Jin Huang
Southwest University, China
Title: Focus on surface modification of cellulose nanocrystals to enhance mechanical properties of bio-based polyesters
Biography
Biography: Jin Huang
Abstract
Due to increasing concern about the environmental protection and the substitute of fossil resources, the development and applications of sustainable materials derived from biomass resources have aroused great interest. Especially, the bio-based polyester including poly(lactic acid) (PLA), poly(butylene succinate) (PBS), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3,4)HB) etc., have been extensively attempted to develop environment-friendly materials and products. Furthermore, it is highlighted that the unique properties of nano-filler contribute to the enhancement of mechanical performances for polymeric materials. In comparison with inorganic nano-fillers, cellulose nanocrystal exhibits many advantages including renewability, biodegradability, biocompatibility, high specific modulus and so on, and shows a rod-like morphology and highly crystalline. As well known, the interface between nano-fillers and polymer matrix is the key issue to determine stress transferring among components, organization of polymer matrix and distribution of nano-fillers. Moreover, the strategies of small molecule-conjugation and polymer-grafting towards cellulose nanocrystals have been applied to regulate surface physicochemical properties, and hence to improve interfacial interaction and even formed chemical linkage between nano-filler and matrix, which gave high mechanical performances for the nanocomposites of cellulose nanocrystal-filled bio-based polyesters. For the bio-based polyester matrix, surface acetylation of cellulose nanocrystals was conducive to promoting their interfacial compatibility with hydrophobic polyester matrix together with an enhancement in mechanical properties of the as-prepared nanocomposites. With an increase of surface acetylation degree, the discrepancy in the surface energy between cellulose nanocrystal surface and polyester matrix gradually decreased, resulting in better affinity and stronger interaction between two components. Hence, homogeneous distribution of acetylated cellulose nanocrystals in polyester matrix was improved, which contributed to optimized reinforcement cellulose nanocrystal with less loss of elongation of the nanocomposites.