棉纤维/季铵盐接枝共聚物的合成及抗菌性能研究

采用硝酸铈铵为引发剂,在棉纤维表面引发甲基丙烯酸二甲氨基乙酯(DMAEMA)接枝聚合,并使接枝的DMAEMA季铵化,以赋予棉纤维良好的抗菌性能。实验对影响DMAEMA接枝率的关键因素进行了细致研究,发现,当φ(DMAEMA)为10%,引发剂浓度为20 mmol/L,pH为1～1.5时,在45℃反应5 h后,得到较好的接枝效果。同时发现,溶剂类型对棉纤维/DMAEMA接枝共聚物的季铵化反应影响很大,丙酮对季铵化最为有利。接枝率的提高可加强棉纤维/季铵盐接枝共聚物的抗菌性能;与单独采用溴代正丁烷为季铵化试剂相比,先后采用溴代正丁烷和溴代十二烷作为季铵化试剂,所得材料的抗菌性能更为优良,说明长链季铵盐聚合物与短链季铵盐聚合物间存在协同抗菌作用。

Synthesis of Cotton Fiber/QAS Grafting Copolymer and Its Antibacterial Characterization

An excellent antibacterial cotton fiber/QAS copolymer was synthesized by a two step method. Dimethyl amino ethyl methacrylate (DMAEMA) was first grafted onto the surface of cotton fiber using ceric ammonium nitrate as the initiator, followed by quaternization with alkyl bromide agents. The optimum grafting conditions were found as following: the concentration of DMAEMA and initiator were 10%(φ) and 20 mmol/L, respectively; the reaction time, solution pH and reaction temperature were 5 h, 1~1.5 and 45 ℃, respectively. Moreover, it was found that the type of solvents had a great effect on the quaternization of grafted DMAEMA, and the best solvent was acetone. The antibacterial activity of the cotton fiber/QAS copolymers depended on the grafting ratios of antibacterial monomers on the cotton fiber. Furthermore, the alkyl chain length of QAS substitution had a significant effect on the antibacterial performance. The grafted DMAEMA cotton fibers quaternized by using mixture of butyl bromide and dodecyl bromide possessed better antibacterial performance than that with butyl bromide alone.