共查询到18条相似文献,搜索用时 312 毫秒
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采用硝酸铈铵-纤维素纤维氧化还原体系引发丙烯酰胺在粘胶纤维上接枝共聚反应,探讨了引发剂浓度、体系硝酸浓度、单体比、反应温度和时间诸因素对产物平衡接枝率的影响及接枝共聚机理,IR表征产物具有预期的结构。 相似文献
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氧化还原引发下的淀粉、丙烯酸反相乳液聚合 总被引:3,自引:0,他引:3
以环己烷为连续相,Span20为乳化剂,采用氧化还原引发体系,通过反相乳液聚合技术,合成淀粉、丙烯酸接枝共聚物。并用红外光谱对共聚物进行了表征。研究结果表明:采用氧化还原引发剂可使聚合反应低温快速进行,在过硫酸钾为3.1mmol/L,亚硫酸氢钠为3.1mmol/L,单体丙烯酸浓度为2.6mol/L,反应温度为30℃,反应时间为3h,乳化剂浓度为5%时,单体转化率为92.6%、淀粉接枝率为43.2%、淀粉接枝效率56.4%。 相似文献
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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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羧甲基纤维素与甲基丙烯酸接枝共聚的研究 总被引:5,自引:0,他引:5
以硝酸铈铵-乙二胺四乙酸为氧化还原引发剂,在N2保护下,羧甲基纤维素钠与甲基丙烯酸进行接枝共聚反应。研究了羧甲基纤维素接枝率、甲基丙烯酸转化率与引发剂浓度、单体浓度、反应时间、反应温度之间的关系。 相似文献
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PP熔融接枝AMPS的研究 总被引:3,自引:2,他引:1
以过氧化二异丙苯(DCP)为引发剂,采用反应挤出技术制备了聚丙烯接枝2-丙烯酰胺-2-甲基丙磺酸共聚物(PP-g-AMPS)。研究了引发剂、单体及第二单体丙烯酰胺(AM)用量、以及温度、螺杆转速等工艺条件对接枝共聚反应的影响,用红外光谱对制备的接枝物进行了表征。结果表明:PP熔融接枝AMPS反应的适宜温度范围及螺杆转速分别为190~200℃和25Hz;接枝共聚反应中DCP及AMPS的最佳用量分别为PP的0.3%和4.0%;添加一定量的AM有利于接枝产物接枝率的提高,AM的最佳用量为PP的0.5%;AM的加入在一定程度上抑制了PP的降解。 相似文献
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聚丙烯无纺布预辐射固相接枝丙烯酸的研究 总被引:1,自引:0,他引:1
以聚丙烯(PP)无纺布为基材,以丙烯酸为单体,进行预辐射固相接枝聚合,考察了外部环境、辐射剂量、温度、反应时间、单体用量、介质、阻聚剂、交联剂对接枝率的影响。结果表明,通过预辐射固相接枝聚合方法,可将丙烯酸单体接枝在PP无纺布上,辐射剂量增大可提高接枝率;反应时间对接枝率的影响在低、高温阶段有所不同。最佳反应条件为:氮气环境,辐射剂量大于50 kGy,反应温度65℃,反应时间3 h,单体浓度30%,反应介质为水,阻聚剂0.8 g,交联剂用量为5 mL。 相似文献
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Graft copolymerization of corn starch with acrylamide using ceric ammonium sulphate/citric acid initiation system has been studied under nitrogen atmosphere in aqueous medium. The grafting parameters are favored by increasing monomer concentration and reaction time but are affected by higher concentration of initiator and high temperature. The optimum conditions established for grafting were as follows: the concentration of initiator, 0.003 mol/L; the concentration of citric acid, 0.03 mol/L; monomer/starch, 1:1 feed ratio (w/w); reaction time, 3.0 h; and temperature, 35°C. The extent of grafting was examined by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. Both swelling power and solubility increased with the increase in temperature. Graft copolymerization increased swelling power and reduced solubility. Rapid visco‐analyzer pasting profile was studied. Graft copolymerization of corn starch results in high pasting temperature, high peak viscosity, and setback as compared with native starch. Breakdown was retarded at low percentage grafting (6.60%) but increased at high percentage grafting (60.27%). POLYM. COMPOS. 28:47–56, 2007. © 2007 Society of Plastics Engineers 相似文献
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研究了Fe2+-H2O2-二氧化硫脲体系引发绒毛浆与甲基丙烯酸甲酯的接枝共聚。考察了该引发体系下反应温度、反应时间、过氧化氢用量、二氧化硫脲用量、单体浓度和液比对接枝率和接枝效率的影响。并用红外光谱对接枝纤维产物进行了鉴定。结果表明,二氧化硫脲的加入能有效地使接枝共聚得以顺利进行;适当地提高温度,增加单体浓度,控制合适的二氧化硫脲用量都能提高接枝率和接枝效率,并在较短的时间就能成功接枝;接枝效率几乎不受液比的影响,一般维持在90%以上,接枝过程产生的均聚物极少。 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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玉米淀粉/丙烯酰胺接枝型高吸水性树脂的合成 总被引:9,自引:1,他引:8
本文以硝酸铈铵为引发剂 ,研究了单体浓度、引发剂浓度、反应温度和反应时间等因素对玉米淀粉与丙烯酰胺接枝共聚制备高吸水性树脂的影响 ,通过反应条件和正交试验 ,确定了最适宜的反应条件和工艺路线 ,制备出了吸水率在 4 5 0~ 70 0g·g-1的玉米淀粉接枝型高吸水性树脂。 相似文献
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Radiation‐induced graft copolymerization of α‐methyl styrene (AMS), butyl acrylate (BA) monomers, and their mixture was investigated on poly(etheretherketone) films. The graft polymerization was carried out using ethyl methyl ketone as the medium for the copolymerization and the maximum degree of grafting of 27% was achieved. It was observed that the grafting is significantly influenced by the reaction conditions, such as reaction time, preirrradiation dose, monomer concentration, monomer ratio, and the reaction temperature. The degree of grafting increases as the monomer concentration increases up to 30%, beyond which a decrease in the grafting was observed. The degree of grafting showed a maximum at 40% BA content in the monomer mixture. The temperature dependence of the grafting process shows decreasing grafting with the increase in the reaction temperature. The presence of AMS and BA grafts in the film was confirmed by FTIR spectra. The relative change in the PBA/PAMS fraction with respect to the reaction temperature has been found in this study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Graft copolymerization of acrylic acid (AA) onto polyphenylene sulfide (PPS) nonwoven initiated by low temperature plasma was studied. The effects of various conditions on graft reaction and the grafting rate were investigated. SEM images showed that PPS nonwoven was grafted, and the graft copolymerization only occurred on the surface of PPS. It may be due to the chain transference going with the graft copolymerization. It was found that with the increasing of plasma power, treatment time, space between electrodes, monomer concentration, and temperature of graft polymerization, the grafting rate increased at first, went to the top, and then decreased. The PPS nonwoven surface graft reaction could be optimized by the following processing conditions: 120 s of plasma treatment time, 50 W of plasma power, 1.5 cm of space between electrodes, 30% (w/w) of monomer concentration, and 50°C of temperature of graft polymerization. Measurement of XPS showed that the peak of C1s of graft polyacrylic acid was existed, and the peak area increased with the increase of the grafting rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5884–5889, 2006 相似文献