光辅助引发制备高相对分子质量聚丙烯酸钠

以丙烯酸和氢氧化钠为原料,过硫酸铵、亚硫酸氢钠和V-50为引发剂,采用光辅助引发聚合法对聚丙烯酸钠的制备进行了研究。考察了各引发剂配比、pH值、反应温度等对聚合结果的影响,得到的较佳反应条件为:pH=7,(NH4)2S2O8与NaHSO3质量分数总和为0.075%,V-50质量分数0.02%,m((NH4)2S2O8)∶m(NaHSO3)=2∶1,反应温度20℃,单体质量分数35%。在上述较佳条件下,产物的相对分子质量可达1 340万,溶解时间26min。     

光引发聚合阴离子型聚丙烯酰胺工艺及其产品絮凝效果的研究

采用光引发聚合方式,以丙烯酰胺(AM)和氢氧化钠(NaOH)为原料,采用前水解法合成阴离子型聚丙烯酰胺(PHP).研究了PHP光合成的影响因素,结果表明:采用光引发聚合的方式合成PHP是可行的.通过正交实验,确定了光引发聚合的影响因素顺序及最佳工艺参数;对最佳工艺合成的产品进行絮凝效果测试,其絮凝性能达到商品PHP的要求,对细粒度、富含高岭土的难沉降煤泥水絮凝沉淀效果明显.     

甲基丙烯酰氧乙基三甲基氯化铵和丙烯酰胺的光辅助引发聚合

以丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,在金属卤化物灯照射和引发剂作用下,通过水溶液聚合法合成阳离子型聚丙烯酰胺P(AM-DMC)。考察了单体质量分数、引发温度、引发剂质量分数、溶液pH值和单体配比等对聚合物特性黏数和溶解性的影响。在单体质量分数30%,阳离子度10%～30%,引发剂质量分数0.0048%,pH值4,引发温度15℃条件下,产物的特性黏数可达10dL/g以上,溶解时间低于40min。用红外光谱对聚合物的结构进行了确认。     

阳离子聚丙烯酰胺的光引发合成及絮凝性能研究

采用光引发聚合方式,以丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为共聚单体,合成了阳离子度为16.03%,特性粘数为548mL/g的阳离子聚丙烯酰胺絮凝剂。采用红外光谱对阳离子聚丙烯酰胺的结构进行了表征,并对合成的CPAM聚合物的絮凝性能进行了研究,研究结果表明:在最佳药剂用量条件下,阳离子聚丙烯酰胺在处理灰分高、粒度细的难沉降煤泥水时,沉降速度为39.2cm/m in,透光率可达98.9%,适宜的阳离子度为16.03%。     

光引发合成阳离子聚丙烯酰胺及其性能研究

实验以光引发聚合方式,研究了丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)共聚反应合成阳离子聚丙烯酰胺(CPAM)的优化工艺条件.结果表明:在吐温-80添加量为1%,单体总质量分数为32%,n(DMC)∶n(AM)=1∶5,pH=5.5,光引发剂用量40 μL,引发时间0.5 h,反应温度20℃条件下,合成的...     

光引发玉米淀粉-丙烯酸反相乳液接枝共聚合制备高吸水性树脂

采用2,2-二甲氧基苯基苯乙酮、二苯甲酮及2,4,6-三甲基苯甲酰基-二苯基氧化膦等多种光引发剂,引发玉米淀粉-丙烯酸/水/煤油/失水山梨醇单油酸酯+壬基酚聚氧乙烯醚反相乳液接枝共聚合,探讨了光引发剂的种类和浓度、玉米淀粉和乳化剂的用量及光照时间对反相乳液接枝共聚合的影响。实验结果表明,多种光引发剂都可引发玉米淀粉-丙烯酸反相乳液接枝共聚合,30m in内单体转化率达到65.31%~92.61%。将玉米淀粉-丙烯酸反相乳液接枝共聚物适度交联,可制得颗粒状高吸水性树脂,交联剂的含量和加入方式都影响树脂的吸水性能。二次聚合可提高树脂的吸水倍率和耐盐性能;扫描电镜观察显示,二次聚合结束时乳胶粒子的粒径增大。     

光引发长链正构烷烃多氯代反应机理与动力学

Based on the mechanism analysis of the polychlorination of long chain n-alkanes by photo-initiation,a kinetic model was developed. The model parameters were obtained by the method of non-linear fitting. The influences of luminous intensity and concentration of molecular chlorine on the rate of polychlorination are demonstrated by the model. If the luminous intensity is adequate, the polychlorination rate of n-alkane is only controlled by the flow rate of molecular chlorine in a wide range of temperature, and the changes of temperature and luminous intensity have less effect on the reaction rate. In addition, the predictions of chlorine content of polychlorinated n-alkane calculated with the model agree very well with experimental results.     

Mechanism and Kinetics of Polychlorination of Long Chain n-Alkanes by Photo-Initiation

Based on the mechanism analysis of the polychlorination of long chain n-alkanes by photo-initiation, a kinetic model was developed. The model parameters were obtained by the method of non-linear fitting. The influences of luminous intensity and concentration of molecular chlorine on the rate of polychlorination are demonstrated by the model. If the luminous intensity is adequate, the polychlorination rate of n-alkane is only controlled by the flow rate of molecular chlorine in a wide range of temperature, and the changes of temperature and luminous intensity have less effect on the reaction rate. In addition, the predictions of chlorine content, of polychlorinated n-alkane calculated with the model agree very well with experimental results.     

Non-steady-state model for kinetics of free radical polymerization, 3. Direct photo-initiation

The non-steady-state kinetics of directly photo-initiated polymerization were studied theoretically. Taking account of the facts that the amount of monomer consumed in propagation is much more than that in initiation for a process producing high polymer and that the rate constant of chain termination is much larger than that of chain propagation or transfer, a few very close approximations were adopted to solve the set of kinetic differential equations of the polymerization under consideration. The inexplicit function method developed in a previous paper of this series for the derivation of the molecular weight distribution function is still valid in this work. Some numerical computation was implemented to show the tendency of free radical concentration decay and the plots of molecular size distribution.     

光敏引发AM-DAC共聚物的合成研究

以丙烯酰胺（AM）和丙烯酰氧乙基三甲基氯化铵（DAC）为原料,在紫外光照射和水溶性复合光敏引发剂作用下,通过水溶液自由基共聚法合成了阳离子型聚丙烯酰胺共聚物（CPAM）。探讨了光敏引发合成过程中复合光敏引发剂用量、单体质量分数、单体配比及乙二胺四乙酸二钠（EDTA-2Na）用量等因素对聚合物相对分子质量、转化率、阳离子度、溶解时间等的影响。得出最佳反应条件为：单体质量分数20%,DAC与AM摩尔比为1∶9,复合光敏引发剂质量分数为0.05%,EDTA-2Na为单体质量的0.03%。运用红外光谱仪对聚合物的结构进行了分析表征。