将具有温度响应的聚N-异丙基丙烯酰胺（ PNIPAm）接枝到电纺纤维素纳米纤维膜上，制备温度响应型纤维素接枝聚N-异丙基丙烯酰胺（PNIPAm-g-Cell）纳米纤维水凝胶。研究接枝单体（N）与纤维素（c）的质量比、反应温度、反应时间和引发剂浓度对产物接枝率、溶胀性和形貌的影响。结果表明，最佳聚合反应条件为m（ N）∶m（ c）＝15∶1、反应温度40℃、反应时间3 h、引发剂浓度为10 mmol／L，得到PNIPAm-g-Cell接枝率和溶胀率分别为35％和31％。与PNIPAm相比，PNIPAm-g-Cell水凝胶的低临界相转变温度（LCST）显著升高，说明亲水性纤维素的引入改变了体系的亲疏水平衡。去溶胀动力学测试表明，0.5 min内接枝率为25％和35％的水凝胶保水率分别降低至93％和61％。说明接枝率越高PNIPAm-g-Cell水凝胶对温度的响应速度越快，对温度越敏感。
Thermally-responsive PNIPAm-g-cellulose nanofibers hydrogels were prepared by thermally-responsive poly ( N-isopropyl acrylamide ) ( PNIPAm ) grafted electrospun cellulose nanofibrous membranes . The effect of mass ratio of monomer and cellulose , reaction temperature , reaction time and amounts of initiator on grafting rate , swelling rate and morphology were investigated .The results show that the optimum reaction condition are as follows:mass ratio of monomer and cellulose in 15∶1 , reaction temperature at 40℃, reaction time for 3 h and initiator concentration of 10 mmol/L, the grafting rate and swelling rate of PNIPAm-g-Cell at 35% and 31%, respectively .Compared with PNIPAm hydrogels , the lower critical solution temperature ( LCST) of PNIPAm-g-Cell hydrogels is obviously increased , indicating that hydrophilic-hydrophobic balance was changed by adding hydrophilic cellulose .Deswelling kinetics of the PNIPAm-g-Cell hydrogels shows that water-retention rate is decreased to 93% and 61% for grafting rate of 25% and 35%, respectively , in initiatory 0.5 min.PNIPAm-g-Cell hydrogels with high grafting rate have greater sensitivity to temperature .
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