共查询到16条相似文献,搜索用时 946 毫秒
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以过硫酸铵为引发剂,制备了羧甲基甲壳素接枝丙烯酸钠共聚物,讨论了反应温度、反应时间、引发剂用量、单体用量对接枝率的影响。红外光谱分析说明接枝反应是由过硫酸铵和羧甲基甲壳素上存在的氨基组成的氧化还原引发体系引发的。 相似文献
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制备了羧甲基甲壳素接枝丙烯酸丁酯共聚物,讨论了反应温度、时间、引发剂用量、溶剂用量、单体用量对接枝反应的影响。最佳反应条件为:羧甲基甲壳素0.3g,溶剂水30mL,引发剂50mg,单体1.2g,反应温度60℃,反应时间3.5h。用红外光谱对接枝产物进行了表征,考察了不同接枝率的产物在10种常见溶剂中的溶解性,结果表明不同接枝率的接枝产物都有水溶性。 相似文献
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用过硫酸钾做引发剂,通过水溶液聚合法制得了木薯淀粉接枝丙烯酸和丙烯酰胺高吸水性树脂.研究了丙烯酸与丙烯酰胺用量比、反应温度及引发剂用量等对吸液性能的影响,分析了木薯淀粉在接枝前和接枝后的结构和性能.最佳反应条件为:丙烯酸/丙烯酰胺质量比1∶3,引发剂过硫酸钾用量是单体质量的0.125%,交联剂N,N'-亚甲基双丙烯酰胺的用量为单体质量的0.167%.反应温度为70℃,反应时间为4 h. 相似文献
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以过硫酸钾为引发剂,在氮气保护下,研究了黄原胶(XG)与丙烯酸(AA)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,探讨了过硫酸钾引发黄原胶接枝丙烯酸共聚反应的基本规律。采用红外光谱(FT—IR)对接枝共聚物的结构进行研究,并初步探讨了接枝机理。 相似文献
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以球形纤维素珠体为原料,丙烯腈(AN)和丙烯酰胺(AM)为单体,硝酸铈铵和过硫酸钾(KPS)为引发剂,制备纤维素珠体-AN-AM接枝共聚物,并通过正交单因素实验,研究了反应温度、引发剂用量、单体用量、反应时间等因素对接枝效果的影响。实验结果表明:当反应温度为60℃,引发剂硝酸铈铵用量为20%,KPS用量为15%(引发剂与单体AN的质量百分比),单体AN浓度为0.75 mol/L,AM浓度为0.28 mol/L,硝酸浓度为0.14 mol/L,反应时间为3 h时,接枝效果最好。此条件下,AN、AM与纤维素的接枝率可达259.4%,接枝效率可达49.40%。 相似文献
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In this article, we have used the potassium persulfate to initiate the graft copolymerization of methyl methacrylate onto cellulosic biofibers in aqueous medium. Different reaction parameters, such as reaction time, initiator molar ratio, monomer concentration, amount of solvent, and reaction temperature, were optimized to get the maximum percentage of grafting (50.93%). The graft copolymers thus formed were characterized by Fourier transform infrared, scanning electron microscopy, X‐ray diffraction, and thermogravimetric, differential thermal analysis, and derivative thermogravimetric techniques. A mechanism is proposed to explain the generation of radicals and the initiation of graft copolymerization reactions. On grafting, percentage crystallinity decreases with reduction in its stiffness and hardness. The effect of grafting percentage on the physicochemical properties of raw as well as grafted fibers has also been investigated. The graft copolymers have been found to be more moisture resistant and also showed better chemical and thermal resistance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011. 相似文献
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黄原胶与丙烯酰胺接枝共聚反应的研究 总被引:1,自引:0,他引:1
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。 相似文献
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淀粉接枝丙烯酸聚合型絮凝剂的合成及絮凝性能研究 总被引:1,自引:0,他引:1
以可溶性淀粉为主要原料,以丙烯酸为接枝单体,硝酸铈铵和过硫酸钾为复合引发剂,采用溶液聚合的方法对糊化处理后的淀粉进行接枝聚合,合成出环保型淀粉衍生物水处理絮凝剂。通过对接枝聚合反应温度、反应时间、引发剂用量以及丙烯酸单体用量等因素对接枝率影响的研究,确定较佳的接枝产物合成条件:淀粉10g,单体丙烯酸用量10mL,硝酸铈铵和过硫酸钾(摩尔比1:1)复合引发体系用量2mmol,接枝反应温度50℃,接枝反应时间3h,接枝率达到43.2%。利用选煤后的废水对其产品絮凝性能进行实验研究,确定较佳的废水絮凝处理条件。 相似文献
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Keisuke Kurita Mitsuo Kawata Yoshiyuki Koyama Shin-Ichiro Nishimura 《应用聚合物科学杂志》1991,42(11):2885-2891
Graft copolymerization of vinyl compounds onto chitin was studied, and an efficient and reproducible procedure has been established, cerium (IV) being used as the initiator. The reactions with acrylamide and acrylic acid onto powdery chitin were carried out under various conditions to elucidate the polymerization behavior in terms of grafting percentage. The amount of cerium (IV) affected the polymerization most strikingly, and grafting percentages showed maxima with suitable amounts of initiator for both the monomers. As a solvent water proved to be superior to aqueous nitric acid except the reaction with a small amount of initiator. Under appropriate conditions, around 240 and 200% grafting percentages were achieved for acrylamide and acrylic acid, respectively. The resulting graft copolymers showed much improved affinity for solvents and hygroscopicity compared to the original chitin. 相似文献