以过硫酸铵为引发剂,在氮气保护下,研究了黄原胶与丙烯酰胺的接枝共聚反应。考察了单体浓度、引发剂浓度、反应温度和反应时间等因素对接枝率及接枝效率的影响,探讨了过硫酸铵引发黄原胶接枝丙烯酰胺共聚反应的基本规律。采用红外光谱、X射线粉末衍射对接枝共聚物的结构进行研究,用热重分析法表征了产物的热性能,并初步探讨了接枝机理。结果表明,过硫酸铵能有效地引发黄原胶与丙烯酰胺的接枝共聚反应,并且接枝率和接枝效率随单体浓度、引发剂浓度、反应温度的变化出现极大值,随反应时间的延长不断上升,直至基本不变。
The graft eopolymefization of aerylamide onto xanthan gum initiated by ammonium persulfate in aqueous medium was studied under a nitrogen atmosphere. The effects of various factors such as monomer concentration,initiator concentration, reaction temperature and time on grafting ratio and grafting eflqciency were studied. The reaction regularity of grafting polymerization on xanthan gum in initiation system was discussed. The graft eopolymers were characterized and analyzed by FT-IR and XRD, and the thermal by TGA. It shows that ammonium persulfate is an efficient initiator for the graft copolymerization, and acrylamide monomers were successfully graft polymerized onto xanthan gum. Both grafting ratio and grafting efficiency have a maximum value while increasing monomer concentration, initiator concentration and reaction temperature, when reaction time increases, grafting ratio and grafting effieieney are increased first and then changed smoothly.