毛竹纳米纤维素的烷基化改性

Research on the alkylation modification of cellulose nanofiber separated from moso bamboo

为了提高毛竹纳米纤维素的分散性及与非极性高分子材料的界面结合性,以硅烷偶联剂(KH-570)为改性剂,分别以乙醇和甲苯为溶剂对毛竹纳米纤维素进行烷基化改性处理,并利用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、X射线能谱(EDAX)和X射线光电子能谱(XPS)对改性后的纳米纤维素性能进行检测分析。结果表明:纳米纤维素的羟基与硅烷偶联剂中的硅羟基之间发生了偶联反应,纳米纤维素的晶型未遭破坏,但是相对结晶度有所下降,烷基化改性后纳米纤维素表面的C和O原子数减少,即C原子与羟基中的O原子连接(C—OH)减少,且纳米纤维素表面羟基和硅烷偶联剂中的硅离子之间发生了配位作用。以乙醇为溶剂硅烷偶联剂改性后的纳米纤维素(E-CNF)的烷基化效果优于以甲苯为溶剂硅烷偶联剂改性后的纳米纤维素(TCNF)。

In order to improve the dispersity and interfacial bonding in the nonpolar polymers, cellulose nanofiber （CNF） isolated from moso bamboo were modified with （ 3-Aminopropyl ） triethoxysilane （KH-570） dissolved in the ethanol and toluene, respectively. The properties of the modified CNF were measured by FTIR, X-ray diffractometer （XRD）, energy dispersive analysis of X-rays （EDAX） and X-ray photoelectron spectrometer （XPS）. The results showed that hydroxyl group in cellulose nanofibers reacted with the Si-OH in KH-570, and the cellulose crystal struc- ture remained unchangeable. However, the relative crystallinity of CNF decreased. The amount of C and O atoms on the CNF surface decreased with the alkylation modification. The results also showed that modified CNF performed better when KH-570 were dissolved in ethanol than in toluene.