酰胺化纳米晶纤维素提高乙烯-醋酸乙烯酯共聚物薄膜阻透性的研究

合成了三种酰胺化纳米晶纤维素，并采用溶液共混成膜法制备了酰胺化纳米晶纤维素（CNC）/乙烯醋酸乙烯醋共聚物(EVA)复合膜材料。通过紫外-可见分光光度计、电子万能试验机和透湿仪研究了酰胺化CNC/ EVA复合膜的光学性能、力学性能以及水蒸气阻隔性，并通过原子力显微镜研究热压处理的EVA复合膜的表面形貌。结果表明，添加三种不同碳链的酰胺化CNC都使 EVA膜的透光率有所降低，当添加量为5 %时，EVA膜透光率仍高达90%。一定程度的热压能够让酰胺化纳米晶纤维素在EVA基体中分散更均匀，使EVA复合膜的透光率提高了2%～3%；随着纳米晶纤维素含量的逐渐增加，三种酰胺化CNC/EVA膜的拉伸强度均逐渐增强，透湿率（WVTR值）均减小；酰胺化CNC含量相同时， 十六胺改性的纳米晶纤维素(CNC-N16)/EVA复合膜的力学性能和水蒸气阻隔效果优于相应的十二胺和正辛胺。

Amide-Based Cellulose Nanocrystals to Improve the Barrier Property of Ethylene - Vinyl Acetate Copolymer (EVA) Film

Three amide-based cellulose nanocrystals were synthesized, and the amide-based cellulose nanocrystals/ethylene-vinyl acetate copolymer (EVA) composite membrane materials were prepared by solution blending film-forming method. UV - visible spectrophotometer, electronic universal testing machine and water vapor permeability instrument were used to characterize the optical, mechanical and water vapor barrier properties of amide-based CNC/EVA composite films. The surface morphology of thermocompression treated EVA films was observed by atomic force microscopy. The results showed that the transmittance of EVA composite films can be decreased by adding three types of amide-based CNC, and the EVA composite film transmittance remained as high as 90% that the added amount of CNC up to 5%. Amide-based CNC can be dispersed in the EVA matrix more uniformly by a certain degree of thermocompression , so that EVA composite film transmittance can be increased by 2% ~3%. With the gradual increase of the content of CNC, three CNC/EVA film tensile strength are gradually increased, the WVTR values are reduced. Same amide-based CNC content, mechanical and water vapor barrier properties of Hexadecylamine modified cellulose nanocrystals (CNC-N16)/EVA films were better than that of dodecylamine and octylamine modified cellulose nanocrystals/EVA films.