茚基钠/甲苯体系引发丙烯腈聚合的研究

本文采用茚基钠作为引发剂,对丙烯腈在甲苯中的聚合进行了研究,考察了引发剂用量、单体浓度、反应时间及反应温度对丙烯腈聚合的影响。发现茚基钠/甲苯体系对丙烯腈聚合反应具有一定的引发活性,且随着引发剂用量增加聚合反应转化率增大,聚合产物的分子量下降;延长聚合反应时间,转化率和分子量都增大;温度对聚合反应转化率影响不大,但对聚合产物分子量有明显影响。用粘度法对聚合产物的粘均分子量进行了表征。     

茚基钠/四氢呋喃体系引发丙烯腈聚合的研究

以茚基钠为引发剂,对丙烯腈在四氢呋喃中的聚合反应进行了研究,考察了引发剂用量、单体与溶剂配比、反应时间及反应温度对丙烯腈聚合的影响,并用粘度法对聚合产物的粘均分子量进行了表征.结果发现茚基钠/四氢呋喃体系对丙烯腈聚合反应具有一定的引发活性,且随着引发剂用量增加聚合反应转化率增大,聚合产物的粘均分子量下降;当单体用量一定时,溶剂的量越多,聚合反应的转化率越低,而聚合产物的粘均分子量却越大;反应时间在1 h之内,延长反应时间,转化率和粘均分子量都增大;反应温度对聚合反应转化率影响不大,但对聚合产物粘均分子量有明显影响.     

α，α’-邻苯二甲基桥联环戊二烯基二价钐配合物催化丙烯腈聚合

文章以α,α＇-邻苯二甲基桥联环戊二烯基二价钐配合物为催化剂,对丙烯腈聚合反应进行了研究。考察了催化剂用量、反应时间及反应温度对丙烯腈聚合的影响,并且用粘度法对聚合产物的粘均分子量进行了表征。发现．α,α＇-邻苯二甲基桥联环戊二烯基二价钐配合物对丙烯腈聚合反应具有较高的催化活性。随着催化剂用量增加聚合反应转化率增大,聚合产物的粘均分子量下降;延长反应时间,转化率和分子量都增大。通过^13C-NMR对所得聚合物的立构规整性进行了表征,所得聚丙烯腈为无规立构聚合物。     

(C9H6CH2C6H4CH2C9H6)Sm催化MMA聚合的研究

文章以α,α’-邻苯二甲基桥联茚基钐胺化物(C9H6CH2C6H4CH2C9H6)Sm为催化剂,对甲基丙烯酸甲酯聚合反应进行了研究,考察了催化剂用量、反应时间及反应温度对甲基丙烯酸甲酯聚合的影响,并且用粘度法对聚合产物的粘均分子量进行了表征。发现α,α’-邻苯二甲基桥联茚基钐胺化物(C9H6CH2C6H4CH2C9H6)Sm对甲基丙烯酸甲酯聚合反应具有较高的催化活性。温度降低,聚合反应转化率增加,聚合产物粘均分子量升高;催化剂用量增加,聚合反应转化率增大,聚合产物的粘均分子量下降;延长反应时间,转化率和分子量都增大。     

α,α’-邻苯二甲基桥联茚基钐胺化物（C9H6CH2C6H4CH2C9H6）SmNPh2催化甲基丙烯酸甲酯聚合

文章以α,α’-邻苯二甲基桥联茚基钐胺化物(C9H6CH2C6H4CH2C9H6)Sm NPh2为催化剂,对甲基丙烯酸甲酯聚合反应进行了研究,考察了催化剂用量、反应时间及反应温度对甲基丙烯酸甲酯聚合的影响,并且用粘度法对聚合产物的粘均分子量进行了表征。发现α,α’-邻苯二甲基桥联茚基钐胺化物(C9H6CH2C6H4CH2C9H6)Sm NPh2对甲基丙烯酸甲酯聚合反应具有较高的催化活性。温度降低,聚合反应转化率增加,聚合产物粘均分子量升高;催化剂用量增加,聚合反应转化率增大,聚合产物的粘均分子量下降;延长反应时间,转化率和分子量都增大。     

羟基偶氮酯引发剂合成双端羟基聚苯乙烯

以偶氮二异丁腈 ,乙二醇为原料合成双 ( 2 -羟乙基 ) 2 ,2′ -偶氮二异丁酸酯。将其作为引发剂 ,合成了遥爪型羟端基聚苯乙烯 ,其分子量为 3 .0× 10 3～ 6 .5× 10 3。讨论了单体浓度、引发剂浓度、聚合反应温度及反应时间对聚合转化率和产物分子量的影响。结果表明 ,聚合转化率和产物分子量随着单体浓度的增加而增加 ;而引发剂浓度增加 ,则聚合转化率明显提高 ,分子量却随之下降 ;温度升高 ,聚合转化率增加 ,产物分子量下降 ;而反应时间主要影响聚合转化率 ,对分子量影响不大。     

链转移剂调控DMDAAC均聚物分子量

以工业级二甲基二烯丙基氯化铵(DMDAAC)为反应单体、甲酸钠或甲醇为链转移剂,选择过硫酸铵-亚硫酸氢钠氧化还原引发体系,采用水溶液聚合法得到分子量在800～9000的PDMDAAC.通过正交实验考察了单体质量分数、聚合温度、聚合时间、聚合体系pH值、引发剂用量、还原剂用量和链转移剂用量对聚合产物特性粘数和单体转化率的影响.研究了链转移剂对PDMDAAC分子量的调控作用及其用量对聚合物特性粘数和单体转化率的影响规律.     

丙烯酸甲酯水包油型微乳液聚合

研究了丙烯酸甲酯水包油型微乳液聚合中,引发剂的种类、用量。反应温度、反应时间、乳化剂的不同、乳化剂含量对聚合反应的影响,用偶氮二异丁腈比用过硫酸钾,单体转化率高,引发剂一次加入与分次加入,单体转化率变化不大,引发剂的最佳用量应为单体含量的1％～2％之间;最佳反应温度在60℃左右;反应时间为6h;用反应性乳化剂十一烯酸钠代替十二烷基硫酸钠,同时与十六烷基三甲基溴化铵(CTAB)作比较,发现用反应性乳化剂十一烯酸钠,不论是单体转化率还是聚合产物的稳定性都比其它两者强。用电子透镜观察聚合得到的聚丙烯酸甲酯微乳液乳胶粒,发现用反应性乳化剂十一烯酸钠反应得到的聚合物的颗粒,平均粒径在30mn,分布呈双峰。测得最低成膜温度为10．8℃。     

新水溶液均相法制备两性聚丙烯酰胺的研究

采用氧化还原引发体系与AIBA为复合分段引发剂,在绝热水溶液体系中进行丙烯酸钠／丙烯酰胺／丙烯酰氧基乙基三甲基氯化铵自由基共聚合。研究了聚合温度、氧化还原引发体系用量、AIBA用量、单体浓度、共聚单体中DAC、AM含量,复合分散剂用量及其HLB值等对聚合反应单体转化率和聚合物特性黏度的影响。聚合物特性黏度随引发剂用量和单体浓度的增大而增大的实验结果证实了该两性聚丙烯酰胺水溶液均相制备过程中凝胶效应的存在。     

反相乳液聚合合成聚丙烯酰胺

以甲苯为介质,Span80/Span20为乳化剂,叔丁基过氧化氢/亚硫酸氢钠氧化还原体系为引发剂,采用反相乳液聚合制备了分子量高达9.4×106的聚丙烯酰胺乳液。研究了乳化剂种类及用量、引发剂种类及用量、油水比、单体浓度,反应温度对共聚物相对分子量、聚合转化率以及聚合反应速率的影响。其最佳聚合配方及工艺条件为:油水体积比为1.4,单体浓度30%,引发剂用量0.003%,乳化剂用量12%,聚合温度30℃。     

Atom transfer radical polymerization of acrylonitrile

Iron(II) chloride coordinated by succinic acid was first used as the catalyst in 2‐chloropropionitrile‐initiated atom transfer radical polymerization (ATRP) of acrylonitrile. N,N‐dimethylformamide was used as a solvent to improve the solubility of the ligand. An iron(II) chloride to succinic acid ratio of 0.5 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. Effects of solvent on polymerization of acrylonitrile were also investigated. The induction period is shorter in N,N‐dimethylformamide than in propylene carbonate and toluene and the rate of the polymerization in N,N‐dimethylformamide is fastest. The molecular weight of polyacrylonitrile agrees reasonably well with the theoretical molecular weight of N,N‐dimethylformamide. The rate of polymerization increases and the induction period becomes shorter with increasing polymerization temperature, and the apparent activation energy was calculated to be 56.5 kJ mol^?1. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1050–1054, 2006     

合成中等分子质量聚丙烯腈聚合反应的研究

以NaClO_3/NaS_2O_5为氧化—还原引发剂,进行了丙烯腈(AN)与衣康酸(ITA)等几种不同单体的的水相沉淀聚合,制得了中等分子质量的聚丙烯腈(PAN)聚合体。系统地考察了引发剂浓度及配比、聚合温度、聚合时间、单体浓度以及第三单体甲基丙烯磺酸钠(MAS)的加入等工艺条件对聚合转化率和聚合物相对分子质量的影响。     

Compatibilization of acrylic polymer–silk fibroin blend fibers. I. Graft copolymerzation of acrylonitrile onto silk fibroin

To synthesize effective compatibilizers for the compatibilization of acrylic polymer–silk fibroin blend fibers, the homogeneous graft copolymerization of acrylonitrile onto silk fibroin, initiated by potassium persulfate–sodium bisulfite redox system in 60 wt % ZnCl₂ aqueous solution was investigated. The percentage graft, percentage efficiency, and molecular weight of the grafted polyacrylonitrile increase with the increase of the concentration of initiator, the concentration of acrylonitrile, and the temperature to optimum values, respectively, and then decrease. With the increase of reaction time, the percentage graft and percentage efficiency increase, whereas the molecular weight of the grafted polyacrylonitrile decreases. The influence of the reactionconditions on the molecular architecture of the graft copolymers is also discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1089–1097, 1998     

Chelating polymer granules prepared by radiation‐induced homopolymerization. I—Kinetic study of radiation polymerization process

Chelating polymer granules containing amidoxime chelating groups were synthesized by radiation‐induced homopolymerization of acrylonitrile monomer. The chemical reactive intermediate polyacrylonitrile was treated with hydroxylamine solution to convert the chemical active cyano groups into the amidoxime groups. Kinetic study of the effects of monomer concentration, radiation dose, dose rate, and temperature on the polymerization process was investigated. It was found that at low monomer concentration, the rate of polymerization is roughly independent on the initial monomer concentration, while at high monomer concentration, 35–65%, a marked acceleration on the rate was observed. The order of the dependence of the initial rate of polymerization on the dose rate is 0.77, which deviates from the classical square‐root law due to the precipitation of the formed polymer. The conversion percent and molecular weight of the produced polymer are inversely proportional to dose rate at constant radiation dose. The activation energy was found to be 2.7 kcal/mol, and the rate constant of initiation is independent of temperature. The effect of type of solvent on the polymerization was studied. DMF solvent of the closest solubility parameter to the solubility parameter of polyacrylonitrile is the best solvent for the polymerization process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1405–1412, 2000     

碳纤维原丝用聚丙烯腈的聚合反应条件

采用水相沉淀聚合法,以过硫酸铵为引发剂,制备了丙烯腈-丙烯酸甲酯-甲叉丁二酸三元共聚物,研究了聚合温度、单体浓度、引发剂浓度对聚丙烯腈共聚物相对分子质量和单体转化率的影响。结果表明:当反应温度为58℃,反应时间为2.5 h,单体质量分数为25%,引发剂质量分数为1.5%时,聚合物的黏均分子质量达3.8×105,单体转化率为79%。     

Reverse atom transfer radical polymerization of acrylonitrile

FeCl₃ coordinated by succinic acid was used as the catalyst for the first time in azobisisobutyronitrile‐initiated reverse atom transfer radical polymerization of acrylonitrile (AN). N,N‐dimethylformamide (DMF) was used as a solvent to improve the solubility of the ligand. A FeCl₃ to succinic acid ratio of 0.5 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. Effects of different solvents on polymerization of AN were also investigated. The rate of the polymerization in DMF is faster than that in propylene carbonate and toluene. The molecular weight of polyacrylonitrile agrees reasonably well with the theoretical molecular weight in DMF. The rate of polymerization increases with increasing the polymerization temperature, and the apparent activation energy was calculated to be 64.8 kJ mol^?1. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 32–36, 2006     

聚合条件对P（AN-co—IA）分子质量分布影响的研究

采用凝胶色谱（GPC）法测定了丙烯腈与衣康酸共聚物P（AN—co—IA）的重均分子质量和数均分子质量,并通过已知聚丙烯腈的重均分子质量数据和数均分子质量数据对所测的分子质量进行校正,进一步计算得到共聚物的多分散系数。同时研究了引发剂用量、单体浓度、聚合温度、聚合时间对P（AN—co—IA）分子质量分布的影响。研究结果表明,P（AN-co-IA）分子质量分布随引发剂用量的增大、聚合单体浓度的增加而变宽,与聚合反应温度、聚合反应时间无明显的变化趋势。