以邻甲基苯酚钾为助引发剂的丁二烯负离子调节聚合

以邻甲基苯酚钾(o—ROK)为助引发剂,正丁基锂(n—BuLi)为引发剂,2G为极性添加剂,二甲苯为溶剂兼链转移剂的丁二烯负离子调节聚合,考察了o—ROK在不同溶剂和不同温度下的溶解性,研究了o—ROK对丁二烯调节聚合能力和聚合物微观结构的影响规律。     

混甲基苯酚钾作助引发剂的异戊二烯负离子调节聚合

采用在有机溶剂中溶解性较好的混甲基苯酚钾(ROK)作助引发剂,研究了正丁基锂(n—BuLi)／ROK／2G／异戊二烯／二甲苯聚合体系的负离子聚合。结果表明,加入一定量的混甲基苯酚钾,聚合转化率无影响;随ROK／n—BuLi(摩尔比)的增加,聚合过程发生链转移,当ROK／n—BuIJi(摩尔比)为0．8时,链转移数高达80;聚合物的相对分子质量由70000降至800左右;无2G存在时,聚合物的1,2-结构和3,4-结构质量分数均呈上升趋势,而添加2G时,2种结构质量分数则呈下降趋势,并建立了微观结构与ROK用量的定量关系式.     

间甲基苯酚钾为调节剂的丁二烯负离子聚合反应

在正丁基锂(n-BuLi)／间甲基苯酚钾(m—ROK)／二乙二醇二甲醚／丁二烯／二甲苯的负离子聚合体系中,研究了m—ROK用量对链转移反应、聚丁二烯相对分子质量及微观结构的影响。结果表明。当m—ROK／n—BuLi(摩尔比)小于0．5时,聚丁二烯的特性黏数和相对分子质量迅速下降,链转移次数增加;当m—ROK／n—BuLi(摩尔比)大于0．5时,则不遵循此变化规律。m—ROK的加入明显加宽了聚丁二烯的相对分子质量分布。增加m—ROK用量时,聚丁二烯的微观结构中1,2-结构质量分数下降,顺式-1,4-结构和反式-1,4-结构质量分数增加。     

以邻甲基苯酚钾为助引发剂的异戊二烯负离子调节聚合

采用邻甲基苯酚钾(o-ROK)为助引发剂,研究了正丁基锂(n-BuLi)/o-ROK/2G/异戊二烯/二甲苯聚合体系的聚合规律.结果表明,加入o-ROK对异戊二烯转化率影响不大;o-ROK/Li(摩尔比,下同)从0增加到0.5时,链转移数(Nt)迅速增大;当o-ROK/Li大于1.0时,M变化缓慢;聚合物的1,2-结构和3,4-结构摩尔分数随o-ROK/Li的增大而减少,1,4-结构的摩尔分数则升高.当o-ROK/Li大于0.5时,曲线的变化趋势变缓.这表明体系中活性种PLi·2G络合体的调节结构能力大于PK,PLi以及它们的缔合体等活性种.     

间甲基苯酚钾为调节剂的异戊二烯负离子聚合反应

考察了间甲基苯酚钾(m-ROK)用量对正丁基锂(n—BuLi)／m—ROK／二乙二醇二甲醚／异戊二烯／二甲苯负离子聚合体系的链转移反应、聚异戊二烯相对分子质量及微观结构的影响。结果表明,当m—ROK／n—BuLi(摩尔比)小于0．5时,聚异戊二烯的特性黏数和相对分子质量迅速下降,链转移次数增加;当m—ROK／n—BuLi(摩尔比)大于0．5时,则不遵循此变化规律。m—ROK的加入明显加宽了聚异戊二烯的相对分子质量分布。增加m—ROK用量时,聚异戊二烯微观结构中1,2-结构和3,4-结构质量分数下降,1,4-结构质量分数增加。     

醇钾和酚钾助引发剂在负离子聚合中的应用研究进展

介绍了醇钾和酚钾作为助引发剂的负离子聚合机理,综述了醇钾和酚钾作为助引发剂在负离子聚合中的应用研究进展,醇钾和酚钾主要调节了聚合物的序列结构和微观结构,引发了链转移反应,对聚合物可实现功能化。     

氧对正丁基锂引发的丁二烯负离子聚合的影响

分别研究了两种溶剂对氧的吸附和脱附作用;氧对正丁基锂的反应历程以及对由正丁基锂引发的丁二烯负离子聚合过程的影响。     

乙二醇二乙氨基乙基丁基醚存在下的丁二烯负离子聚合

研究了以乙二醇二乙氨基乙基丁基醚(GABE)为调节剂,正丁基锂为引发剂的丁二烯负离子聚合的聚合动力学及聚合物的微观结构。结果表明,随着GABE用量的增加,丁二烯的聚合速率增加,聚丁二烯中1,2-结构质量分数增加,聚合温度升高,聚合速率增加,但聚丁二烯中1,2-结构质量分数有所降低。     

负离子聚合双锂引发剂研究进展

总结了用于负离子聚合的双卤代烷烃类、萘类、双烯烃类及其齐聚物双锂引发剂,以及其他新型双锂引发剂的类型、合成方法及特点的研究进展。     

Anionic telomerization of butadiene with toluene and diphenylmethane: microstructure and molecular weight

The frequency of chain transfer of polybutadienyllithium to toluene and diphenylmethane is increased in the presence of N, N, N′, N′-tetramethylethylenediamine. When the reactor is fed with monomer at a constant rate, the molecular weight of telomer falls steeply as the ratio [base]:[lithium] increases from zero to unity but much more slowly thereafter. Whenever an anionic chain end has a penultimate 1,2-placement, cyclization to form a vinylcyclopentane competes with propagation the more favourably the lower the monomer concentration. In consequence, telomers prepared in toluene have a far greater cyclic content than those prepared in diphenylmethane.     

Studies on chain transfer reaction in butadiene polymerization initiated with n‐butyl lithium and novel promoter potassium para‐methylphenoxide

The chain transfer reaction was examined in the anionic telomerization of butadiene with n‐BuLi as the initiator, potassium para‐methylphenoxide (ROK) as the novel promoter, mixed xylene as the transfer agent as well as a solvent in the presence of diglyme as the polar modifier. Effects of ROK, diglyme, and the polymerizing temperature were studied. It was demonstrated that they all promote the chain transfer reaction. The relative constant of chain transfer to the solvent was also calculated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1215–1218, 2005     

以环氧大豆油为偶联剂的丁二烯负离子均聚合

研究了以正丁基锂为引发剂,四氧呋喃（THF）为调节剂,环己烷为溶剂,环氧大豆油为偶联剂的丁二烯负离子均聚合。结果表明,随着偶联剂和THF用量的增加。偶联效率都是先升高后降低;随着温度的升高,偶联效率升高;偶联后聚合物相对分子质量分布变宽。     

以叔戊氧基钾为调节剂的丁二烯和异戊二烯共聚合

以正丁基锂为引发剂,叔戊氧基钾(KTA)为调节剂,环己烷为溶剂,将丁二烯和异戊二烯于50℃进行共聚合。结果表明,随着KTA用量的增加,聚合速度加快;共聚物无规化程度增加;与以N,N,N’,N’-四甲基乙二胺为调节剂的结果截然相反。     

Effects of oxygen on anionic butadiene telomerization in hydrocarbon solvents

During the development of an anionic butadiene telomerization process consisting of two stages, initiator preparation and telomerization, in a hydrocarbon solvent which contained a chain-transfer agent, we found that a small amount of oxygen accidentally introduced caused an unusually large decrease in the telomer viscosity. Based on the degree of such decrease due to the addition of oxygen at the two stages and based on the rather modest reactivity of oxygen with organosodium compounds, we concluded that free oxygen was catalytically involved in the telomerization process. The results of kinetic and transmetalation studies indicated that only the chain-transfer reaction was accelerated catalytically by free oxygen.     

Anionic copolymerization of butadiene and styryl-terminated polystyrene macromonomers

Summary For the preparation of graft copolymers of the type poly (butadiene-g-styrene), possibilities were investigated both of obtaining a living anionic copolymerization of butadiene and styryl-terminated polystyrene macromonomers and of assessing the necessary analytical prerequisites for determining the conversion. The course of this copolymerization can be observed by combining gravimetry with SEC. With the initiator system sodium tert-butoxide /n-butyl lithium there are only a few deviations from the statistically ideal course of copolymerization and the macromonomer is almost completely incorporated into the copolymer.