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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。
Acrylic monomer (AA) was grafted on nanocrystalline cellulose whiskers (NCW) using K2S2O8 as initiator to prepare acrylic acid graft modified nanocellulose whiskers. The grafting product was characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The grafting yield and surface substituent groups were calculated by conductometric titration content. The effects of reaction conditions on grafting yield and grafting efficiency were studied. The results showed that under the conditions of initiator concentration of 4mmol / L, priming time of 5min, molar ratio of nanocellulose whisker to acrylic acid monomer of 1: 1.5 and reaction time of 6h, the grafting yield was 14.09% Acrylic grafted nanocellulose whiskers. Experiments show that NCW grafted with acrylic acid, the grafting rate of 14.09% of the products and NCW have similar surface morphology and thermal properties; TEM analysis shows that the dispersion of graft products has been improved; surface substitution groups The content tests showed that the content of hydrophilic disperse groups on the surface of grafted products increased more than 5 times than that of NCW.