共查询到18条相似文献,搜索用时 250 毫秒
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降解淀粉与乙烯基单体AA-AN-AM接枝共聚物复鞣剂的合成及应用研究 总被引:4,自引:2,他引:4
氧化降解的玉米淀粉与丙烯酸(AA)、丙烯腈(AN)和丙烯酰胺(AM)在引发剂(NH4)2S2O8作用下进行了接枝共聚合反应,制得改性淀粉复鞣剂。研究了单体浓度及配比、引发剂浓度等因素对接枝共聚合反应的接枝率、单体转化率、接枝效率等的影响,用红外光谱对接枝共聚物的结构进行了分析表征,同时进行了应用实验。 相似文献
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以过硫酸铵为引发剂,研究了酸解氧化淀粉与醋酸乙烯酯的接枝共聚反应.探讨了淀粉与单体比例对接枝共聚反应的影响;选择接枝反应温度、PH值为自变量,应用中心组合设计,考察淀粉接枝反应过程中接枝百分率、接枝效率和单体转化率的变化,采用多元二次回归和响应面分析等手段,对接枝反应进行优化.研究发现,酸解氧化淀粉与醋酸乙烯酯接枝共聚反应的最佳条件为单体与淀粉质量比为80:100、接枝反应温度为70℃左右、PH值为4左右,对应接枝百分率为28.2%,接枝效率为49.1%,单体转化率为99.8%. 相似文献
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将适当的氧化降解淀粉与乙烯基类单体在引发剂作用下进行接枝共聚合,将其用作复鞣剂进行应用试验,优化选择得到了改性淀粉复鞣剂DF-Ⅰ。应用结果表明:该复鞣剂具有选择填充性显著,成品革丰满、柔软、粒面细腻、有弹性、染色性能好等特点。 相似文献
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乳液接枝共聚法改性淀粉的制备及表征 总被引:6,自引:0,他引:6
以氧化降解淀粉为骨架,丙烯酸(AA)、丙烯腈(AN)、甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为接枝共聚单体,过硫酸铵与亚硫酸氢钠组成的氧化-还原体系为引发剂,十二烷基硫酸钠(SDS)、Span80和亚硫酸化鱼油为乳化剂,采用乳液接枝共聚法制备可用于皮革复鞣的改性淀粉产品。以单体配比、引发剂用量、反应温度和反应时间为考察因素,产品稳定性、接枝率、接枝效率、单体转化率和在复鞣中应用的效果等为综合考察指标,经正交试验优化出的较佳合成条件为:单体配比(AA/1 0 g;AN/5 g;MMA/1 5 g;BA/1 0 g) ;引发剂用量3 0g;反应温度45℃;反应时间2 5h。此时接枝率、接枝效率、单体转化率分别为:1 5 6 8% ;82 6% ;95 %。用FT -IR、DSC、XRD和SEM对产物进行了表征,结果表明:乙烯基类聚合物已成功地接枝于降解淀粉骨架上 相似文献
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淀粉烯丙基化预处理型PMA接枝淀粉的研究 总被引:1,自引:1,他引:0
研究淀粉烯丙基化预处理型PMA接枝淀粉的制备方法及性能.通过对淀粉原料进行醚化预处理,在淀粉大分子上引入碳-碳双键,再将这种含有碳-碳双键的淀粉与丙烯酸甲酯单体进行接枝共聚合反应,大幅度提高了淀粉与丙烯酸甲酯单体接枝共聚合反应的接枝效率,改善了烯丙基化预处理型PMA接枝变性淀粉浆料(AS-g-PMA)的上浆性能.研究结果表明,当淀粉醚化取代度在0.01~0.043范围内时,这种醚化预处理方法可以使淀粉对丙烯酸甲酯的接枝效率比直接接枝提高10%~20%,并能显著改善接枝淀粉浆料对纤维的粘附性能以及浆膜性能.试验证实AS-g-PMA型接枝变性淀粉浆料的醚化取代度以0.011~0.023为宜. 相似文献
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以马铃薯淀粉为接枝骨架,过硫酸铵为引发剂,醋酸乙烯酯(VAc)为接枝单体进行接枝共聚。考察了不同引发剂浓度、反应温度、反应时间、单体配比、淀粉浓度对单体转化率、接枝率及接枝效率的影响,确定最佳工艺条件为:引发剂浓度18 mmol/L,反应温度60℃,反应时间3.5 h,单体配比2.5:1,淀粉浓度5%。并通过扫描电镜,X射线衍射,傅里叶红外光谱对淀粉接枝共聚物进行分析,结果表明:淀粉接枝共聚后,淀粉的微观形貌已经改变,结晶度降低且醋酸乙烯酯成功接枝在马铃薯淀粉上。 相似文献
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采用丙烯酸(AA)单体对酸解玉米淀粉进行接枝,讨论了丙烯酸单体与玉米淀粉剩基(AGU)配比、丙烯酸单体pH值、引发剂用量、反应时间及温度对接枝产物接枝率、抱水性及PVID值的影响,并用红外光谱(FTIR)对接枝产物进行表征。试验得出丙烯接枝酸解玉米淀粉优化工艺为:n(AA):n(AGU)=2:1,丙烯酸单体pH值为6、引发剂n(H2O2)/n(FeSO4)=1.98,n(H2O2)=0.529mmol,接枝反应温度为50℃及时间为3h。所得接枝产物接枝率为5.14%,羧基含量为4.02%;接枝产物的抱水性为10.5mm,PVID值为0.34,各项性能与海藻酸钠相近,可作印花原糊用。 相似文献
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The grafting of acrylamide (AM) onto maize starch in aqueous medium initiated by ceric ammonium nitrate (CAN) has been studied gravimetrically under nitrogen atmosphere. The effect of concentration of monomer and initiator, polymerization time and reaction temperature has been studied in terms of efficiency of grafting (%GE) and percentage Add-on (%Add-on). The %GE was found to decrease with increase in monomer concentration, but the reverse trend was obtained on increasing the polymerization time and temperature. The maximum %GE was obtained at 45°C when polymerization was carried out for 180 min using [CAN] = 0.004 mol/L and [AM] = 0.141 mol/L in 100 mL of distilled water with 2 g of starch. These graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. The graft copolymers showed enhanced thermal stability than pure starch. Hydrogels were prepared by grafting AM onto gelatinized maize starch followed by saponification of these graft copolymers with NaOH. The maximum water absorption obtained was 170 g/g. 相似文献
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Graft polymerization of vinyl acetate (VAc) onto gelatinized and dissolved granular potato starch has been carried out using an initiation system of ceric ammonium nitrate (CAN)/nitric acid (HNO3) at 50°C. The granular starch was dissolved in an aqueous alkaline solution (0.25 M NaOH) for 24 h before graft reaction. The effects of reaction variables, such as the concentrations of acid, monomer, and initiator, on the grafting parameters of prepared starch/VAc copolymers have been investigated in both grafting methods for comparison. Although the scanning electron microscopy (SEM) images showed a rather similar homogeneous structure for dissolved and gelatinized starch, a higher grafting level, especially at lower monomer concentrations, was obtained for the copolymers prepared using the dissolved starch. A larger number of reactive sites uniformly created on the starch molecules led to greater accessibility of the monomer and improved considerably the grafting efficiency in the grafting conditions using the dissolved starch. The effects of the grafting methods on the microstructure, morphology, and thermal stability of the resulting copolymers have been studied by Fourier‐transform infrared (FTIR) spectroscopy, scanning electron microscopy, and thermogravimetric analysis (TGA), respectively. The TGA results showed that the grafting of VAc onto dissolved starch led to the formation of more thermally stable graft copolymers. 相似文献
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通过自由基聚合反应,在氧化淀粉分子链上接枝苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酸十八酯(ODA)、反应型乳化剂DNS-86与甲基丙烯羟丙基磺酸钠(HPMAS),合成一种阴离子淀粉接枝表面施胶剂,探讨反应型乳化剂DNS-86、甲基丙烯羟丙磺酸钠(HPMAS)和丙烯酸十八酯用量对施胶效果的影响。在甲基丙烯酸羟丙基磺酸钠1.5%,丙烯酸十八酯3%,DNS-862%时,合成的阴离子接枝表面施胶剂与氧化淀粉、硫酸铝复配施胶,能够有效提高施胶效果与环压指数。 相似文献