摘要
以二(二(2-乙基己基)磷酸)异辛酸钕盐(Nd(P_(204))_2EHA)/氢化二异丁基铝(AlH(i-Bu)_2)/二甲基二氯硅烷(Me_2SiCl_2)为催化剂进行异戊二烯聚合。考察了[Al]/[Nd]、[Cl]/[Nd]比、聚合温度和时间对聚合的影响。该催化剂在[Al]/[Nd]为10时,可高活性催化异戊二烯聚合。所得聚合物具有高相对分子质量(Mn^10~5)、窄相对分子质量分布(Mw/Mn<2. 0)、高顺-1,4立构规整性(97. 5%)。催化活性随[Al]/[Nd]在8. 0~15和[Cl]/[Nd]在1. 0~3. 0范围内的增加而提高,反应温度的升高可显著加快聚合速率。聚合物窄的相对分子质量分布和凝胶渗透色谱的单峰曲线,表明该催化体系具有单一活性中心的特点;聚合物的立构规整性基本不受反应条件的影响,顺-1,4结构含量为97. 0%~97. 5%,表明催化剂有高的立体定向性。
ABSTRACT： Neodymium di [ bis （2-ethylhexyl） phosphate 2-ethylhexanoate [ Nd （ P204 ） 2EHA ]/diisobutylaluminum hydride [ A1H （ i-Bu）2 ]/dichlorodimethylsilane [ Me2SiCI2 ] catalyst for isoprene polymerization was examined. The influences of [ A1]/[ Nd] and [ CI]/[ Nd] ratios as well as reaction temperature on the polymerization were investigated. The catalyst works effectively even at a low [A1]/[Nd~ ratio of 10 to afford polymers with high molecular weight （Mn- 105）, narrow molecular weight distribution （Mw/Mn 〈 2. 0）, and high cis-1, 4 stereoregularity （97.5%）. The polymer yield increases with the increment of [A1]/[Nd] ratio from 8 to 15 and [ C1]/[ Nd] ratio from 1. 0 to 3. 0, respectively, and the polymerization rate is accelerated by raising the polymerization temperature. The narrow mo[ecular weight distribution and unimodal gel permeation chromatographic curve of the polymer suggest that the presence of a single active site in the polymerization system. Regardless of reaction conditions, the cis-1,4 contents of the resulting polymers stay in a range of 97.0 % --97.5 %, indicating that the catalyst has high stability of stereospecificity.
作者
王慧军
李华
郑文洁
高可可
胡雁鸣
张学全
Huijun WangI, Hua Li, Wenjie Zheng, Keke Gao, Yanming Hu, Xuequan Zhangz(1. Shandong Non-Metallic Materials Institute, Jinan 250031, China ; 2. Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2018年第9期31-34,共4页
Polymer Materials Science & Engineering
基金
国家科技支撑计划(2014BAE14B00)
