丙烯酸单体接枝纳米纤维素晶须

Nanocellulose Whiskers Grafted with Acrylic Monomers

以K2S2O8为引发剂,在纳米纤维素晶须(NCW)上接枝丙烯酸单体(AA),制备出丙烯酸接枝改性的纳米纤维素晶须。通过傅立叶变换红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等测试方法对接枝产物的性能进行了分析,并采用电导滴定的方法计算了接枝率以及表面取代基团含量。研究了反应条件对接枝率和接枝效率的影响。结果表明,在引发剂浓度为4mmol/L,引发时间为5min,纳米纤维素晶须与丙烯酸单体摩尔比为1∶1.5,反应时间为6h的条件下,得到了接枝率为14.09%的丙烯酸接枝纳米纤维素晶须。实验证明,在NCW上可以接枝上丙烯酸,接枝率为14.09%的产物与NCW具有相似的表面形貌和热性能;TEM分析可知,接枝产物的分散性得到了提高;表面取代基团含量测试表明,接枝产物表面上的亲水性分散基团含量比NCW增加了5倍以上。

Nanocellulose whiskers （NCW） was polymerized with acrylic monomer using potassium persulfate as an initiator. The graft copolymer was characterized using several analytical techniques such as FTIR, TEM, TGA, and the conductometric titration method, which was used to calculate the grafting yield and the contents of surface substituents. The effects of reaction conditions on the graft yield and graft efficiency were investigated. It is showed that the graft copolymer with the grafting yield at 14. 09% was obtained when the concentration of initiator is 4 mmol/L,the molar ratio of NCW and AA is 1：1.5, the initiate time and reaction time are 5 min and 6 h, respectively. The results proved that the acrylic monomers can be grafted onto NCW, which has similar properties as the grafted product that has a better dispersion stability, when their TEM figures were compared. The tests showed that the content of hydrophilic substituents of the grafted product was at least 5 times more than NCW.