Synthesis, characterization, and morphology of poly(tert-butyl vinyl ether-b-isobutylene-b-tert-butyl vinyl ether) triblock copolymers
Synthesis, characterization, and morphology of poly(tert-butyl vinyl ether-b-isobutylene-b-tert-butyl vinyl ether) triblock copolymers
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聚(叔丁基乙烯基醚-b-异丁烯-b-叔丁基乙烯基醚)三嵌段共聚物的合成、表征和形貌
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
S. Gido
中科院分区：
文献类型：
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作者：
Yonghua Zhou;R. Faust;Shujun Chen;S. Gido
研究了异丁烯（IB）与叔丁基乙烯醚（tBVE）在正己烷/CH2Cl2和正己烷/CH3Cl溶剂体系中，在- 80℃下的一锅法活性阳离子序段共聚反应。它是通过所谓的封盖调整技术进行的，包括用1,1-二聚乙烯（DTE）封盖活的PIB链末端，然后在引入tBVE之前加入钛（IV）异丙醇（Ti(OIp)4）以降低刘易斯酸度。用2-氯-2,4,4-三甲基戊烷（TMPCl）代替活性PIB进行了tBVE的均聚/模式嵌段共聚。ln（[M]0/[M]）与时间的线性关系和分子数平均分子量（Mn）与转化率的线性关系表征了活性。13C核磁共振波谱表明，PtBVE具有高度等规性，接近80%的中位二元。通过IB活性阳离子聚合，用DTE封住活性PIB末端，并对Lew进行微调，合成了具有良好定义的PIB-b- ptbve双嵌段共聚物。
The living cationic sequential block copolymerization of isobutylene (IB) with tert-butyl vinyl ether (tBVE) was studied using a one-pot procedure in hexanes/CH2Cl2 and hexanes/CH3Cl solvent systems at −80 °C. It was carried out by the so-called capping-tuning technique, involving the capping of living PIB chain ends with 1,1-ditolylethylene (DTE) followed by addition of titanium(IV) isopropoxide (Ti(OIp)4) to lower the Lewis acidity before the introduction of tBVE. Homopolymerizations/model block copolymerizations of tBVE were carried out using 2-chloro-2,4,4-trimethylpentane (TMPCl) instead of living PIB. The living nature was exhibited by the linear plots of ln([M]0/[M]) vs time and number average molecular weight (Mn) vs conversion. 13C NMR spectroscopy indicated that the PtBVE is highly isotactic with close to 80% meso dyads. Well-defined PIB-b-PtBVE diblock copolymers were synthesized by the living cationic polymerization of IB followed by capping the living PIB ends with DTE and fine-tuning the Lew...