纳米纤维素表面聚丙烯酸丁酯原位修饰  

In-situ surface modification of cellulose nanofibril with poly(butyl acrylate)

作　　者：王璇 贾园[1] 宋立美[1] Wang Xuan;Jia Yuan;Song Limei(College of Chemical Engineering,Xi'an University,Xi'an 710065,Shaanxi,China)

机构地区：[1]西安文理学院化学工程学院

出　　处：《北京林业大学学报》2019年第10期137-146,共10页Journal of Beijing Forestry University

基　　金：陕西省科技厅项目（2019JQ-893）,陕西省科技厅项目（2018JM2021）;西安市科技计划项目（2016CXWL01）,西安市科技计划项目（2019KJWL10）

摘　　要：【目的】由于强亲水的纳米纤维素与有机高分子材料之间的界面相容性差,使其作为一种有前景的增强剂应用受到限制。采用丙烯酸丁酯(BA)对纳米纤维素(CNF)表面进行原位乳液接枝聚合改性可以提高纳米纤维素与聚乳酸等高分子材料的相容性。【方法】本研究优化了纳米纤维素表面接枝聚丙烯酸丁酯(PBA)链接枝率的影响条件,并利用傅里叶红外光谱(FTIR)、X射线衍射光谱(XRD)、透射电镜(TEM)、热重(TG)、X射线光电子能谱(XPS)以及扫描电子显微镜-能量散射X射线微区(SEM-EDS)分析等手段对聚丙烯酸丁酯修饰前后的纳米纤维素进行了表征,利用扫描电子显微镜对改性纳米纤维素与聚乳酸基体的相容性进行了分析。【结果】改性纳米纤维素(PBA-g-CNF)在1 734 cm-1出现了典型的羰基红外吸收;改性纳米纤维素的结晶度指数为48%,较纳米纤维素的61%有所下降;纳米纤维直径由50 nm增加至80~100 nm;最大热失重温度由改性前的340℃增加至改性后的354℃;纳米纤维素中的C和O的原子数比为1.89,改性纳米纤维素的C和O的原子数比为3.76,C和O元素在改性前后纳米纤维素中分布均匀;改性纳米纤维素与聚乳酸的共混膜材料拉伸断面呈现出韧性断裂过程。【结论】聚丙烯酸丁酯改性纳米纤维素是成功的,且改性过程主要发生在纳米纤维素的表面。改性后的纳米纤维素与聚乳酸之间展现了良好的界面相容性。[Objective] Cellulose nanofibril(CNF) is a promising strengthener but is used limitedly since its poor compatibility with organic materials. The graft polymerization of butyl acrylate(BA) via in-situ emulsion polymerization of CNF is adopted to modify its compatibility. [Method] The conditions were optimized to induce the grafting yield of the PBA chains on the surface of CNF. FTIR, XRD, TEM, TGA,XPS and SEM-EDS were used to characterize the PBA-g-CNF, the compatibility of PBA-g-CNF and poly(lactic acid)(PLA) was characterized by SEM. [Result] The results indicated that PBA-g-CNF showed the IR adsorption peak at wavenumber of 1 734. The crystallinity index of PBA-g-CNF was 48%, which was decreased compared with that of CNF(61%). The diameter of nanofibrils increased from 50 nm to 80-100 nm. The maximum degradation temperature of PBA-g-CNF increased by 14 ℃ compared with that of CNF. The C/O ratios of PBA-g-CNF and CNF were 3.76 and 1.89, respectively. C and O element were dispersed uniformly in PBA-g-CNF and CNF. The tensile fracture surface of PBA-g-CNF/PLA composite films showed tough character. [Conclusion] Cellulose nanofibril was succesfully modified by poly(butyl acrylate), and the modification process was mainly occured on the surface of CNF. The PBA-g-CNF showed good interfacial compatibility with poly(lactic acid).

关 键 词：纳米纤维素 丙烯酸丁酯 原位乳液聚合 聚乳酸 界面相容 

分 类 号：TQ35[化学工程]