羧甲基瓜尔胶与DMC-AM二元单体的接枝共聚合

Grafting Copolymerization of Carboxymethyl Guar Gum and DMC-AM Co-Monomers

以高锰酸钾／硫酸引发羧甲基瓜尔胶（CMGG）和丙烯酰胺（AM）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）的接枝共聚合反应制备两性瓜尔胶（AC-GG），考察了引发剂、单体和CMGG浓度及取代度等因素对接枝共聚反应的影响，得到最佳操作条件下的转化率、接枝率和接枝效率分别为92．9％，797％和84．7％．根据Arrhenius方程计算得到296～323K下共聚反应的表观活化能为13．28kJ／mol，表明高锰酸钾是高效引发剂．^13C-NMR证实发生了接枝反应．

The co-monomers of ethyl methylacrylate-trimethylammonium chloride （ DMC ） and acrylamide （AM） were grafted onto carboxymethyl guar gum （CMGG） to synthesize amphoteric guar gum （AC-GG）, with potassium permanganate/sulfuric acid as the initiator. The effects of the concentrations of the initiator, the monomer and CMGG as well as the degree of substitution （DS） of CMGG on the grafting copolymerization were then investigated. The results show that, in the optimal conditions, the polymerization conversion ratio, the grafting ratio and the grafting efficiency are respectively 92.9%, 797%and 84.7%. Moreover, it is found that potassium permanganate is a high-efficiency initiator because the apparent activation energy calculated by Arrhenius equation is up to 13.28 kJ/mol. The grafting is further characterized by means of ^13C-NMR.