细菌纤维素气凝胶接枝甲基丙烯酸二甲氨乙酯的制备

摘要

In order to prepare novel controllable grafted-polymers from bacterial cellulose(BC) aerogels,BC grafted N,N,N'N'N″pentamethyldiethylenetriamine(BC-g-PDMAEMA)was synthesized by electron transfer for atom transfer radical polymerization(ARGET ATRP), using bacterial cellulose aerogels with bromide side-group(BC-Br)as the macroinitiator and N,N,N'N'N″-PMDETA/copper(II)bromide(CuBr2)as catalytic system, vitamin C as reducing agent and 2-(dimethylamino) ethyl methacrylate(DMAEMA)as the comonomer. Molecular weight distribution, element content, chemical structure, thermal stability, crystalline structure and surface morphology of the modified BC aerogels were characterized by gel chromatography, energy dispersive spectrum, Fourier transform infrared spectrometry,X-ray diffraction,scanning electron microscopy and thermal gravity analysis. The results indicate that the BC-g-PDMAEMA polymers are successfully prepared by ARGET ATRP. The molecular weight distribution is 1.27 and the grafting ratio of DMAEMA is 875.76%. After grafting,the diameter of the fiber is increased and the coating layer is formed on the fiber surface. The thermal stability of the BC-g-PDMAEMA polymers increases from 205 ℃ to 230 ℃.%为制备新型细菌纤维素(BC)气凝胶可控接枝聚合物,采用电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP)法,以含溴的细菌纤维素为引发剂、维生素C(VC)为还原剂、N,N,N'N'N″-五甲基二亚乙基三胺(PMDETA)/溴化铜(CuBr2)为催化剂,制备了含聚甲基丙烯酸二甲氨乙酯(PDMAEMA)的细菌纤维素气凝胶规整接枝共聚物.采用能谱分析仪对大分子引发剂元素含量进行测定.借助凝胶渗透色谱、红外光谱、X射线衍射、扫描电镜、热失重分析表征了接枝物结构和性能.结果表明:以细菌纤维素气凝胶为原料,采用ARGET ATRP法成功制备了BC-g-PDMAEMA聚合物,其相对分子质量分布指数为1.27,接枝率为875.76%,接枝后纤维直径增大且在纤维表面形成覆盖层,热稳定性由205 ℃升高到230 ℃.