纳米微晶纤维素的制备、改性及其在纸张阻隔涂布中的应用

Preparation,modification and its appliction of nanocrystalline cellulose in barrier coating of cellulosic paper

以微晶纤维素（MCC）为原料,基于酸水解法制备了纳米微晶纤维素（NCC）.随后,在水/二甲基亚砜反应体系中,以2,3-环氧丙基三甲基氯化铵（GTMAC）为阳离子醚化剂对 NCC进行改性得到了阳离子化的纳米微晶纤维素（CNCC）.最后,对NCC、CNCC在纸张阻隔涂布中的应用进行了初步探讨.实验结果表明,NCC 呈棒状结构,粒径10～80 nm,长度＜400 nm,其水相分散液在光照下呈现特殊的蓝光效应.通过氮元素分析法,测得CNCC的取代度为4．1％；FT-IR、XRD 分析结果确证了 NCC 被成功改性；TEM、TG 分析结果表明,与 NCC相比,CNCC具有较好的分散性和热稳定性.初步应用结果表明,相对于 NCC,CNCC 对涂布纸阻隔性能改善效果较为明显,且当添加量为0．2％时效果最佳,与零添加的涂布纸相比,透气度下降了22．4％,吸水性降低了34．4％.

In the present work,nanocrystalline cellulose was initially prepared from microcrystalline cellulose by sulfuric acid hydrolysis,and subsequently cationically modified with glycidyltrimethylammonium chloride （GT-MAC）in water/DMSO mixture.Eventually,the feasiblity of the application of nanocrystalline cellulose in bar-rier coating of cellulosic paper was investigated.It was found that NCC exhibited a rod-like structure with a di-ameter between 10 and 80 nm and a length less than 400 nm,and displayed good dispersion in liquid suspen-sions.Moreover,CNCC was found to possess adegree of substitution of 4.1% by determination of nitrogen con-tent.Successful modification of NCC was identified by FT-IR and XRD result.More importantly,TEM and TG results indicated that CNCC had remarkable advantage in dispersibility and thermal stability as compared to NCC.The preliminary application experiment showed that,in comparision to NCC,CNCC reinforced cellulosic paper exhibited better barrier properties.Specifically,at an addition of 0.2%,the coated paper showed a desired application efficiency of NCC and CNCC.As compared with the controlled paper,CNCC reinforced cellulosic pa-per showed a 22.4% decrease in air permeability and a 34.4% decrease in water absorbtion,respectively.