权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Studies on the Growing Species in Living Cationic Polymerization and Synthesis of Various Types of Living Polymers

活性阳离子聚合生长物种及各类活性聚合物的合成研究

基本信息

批准号：
08651056
负责人：
HIGASHIMURA Toshinobu
金额：
$ 1.6万
依托单位：
The University of Shiga Prefecture
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

A key to successful living cationic polymerization is the judicious choice of a counterion for a particular growing end. Namely, a suitably nucleophilic counterion stabilize the growing end to lead to living cationic polymerization. To generalize the principle for living cationic polymerization, we examined the feasibility of living cationic polymerization in polar solvents where the dissociated free ionic species may be involved.Living Polymerization of Isobutyl Vinyl Ether(IBVE). At-78ﾟC,living polymerization was induced with the HCI-IBVE adduct(1)/ZnCl_2 system in CH_2Cl_2 and a EtNo_2/CH_2Cl_2 mixture, whereas similar systems with EtAlCl_2 led to conventional cationic polymerization. In these polar media, both systems gave polymers with very similar and low isotacticity (meso<approximately equal>56%), indicating that the propagating reaction is mediated by free ions. Thus, regardless of solvent polarity, or involvement of free ions or ion pairs, living cationic polymerization requi … More res a suitably nucleophilic counteranion.Living polymerization of p-t-Butoxystirene (tBOS). To demonstrate the feasibility of living polymerization by free ions other cationically polymerizable monomers, cationic polymerization of tBOS,which has higher reactivity among stirene derivatives, was examined with the 1/ZnCl_2 initiating system at-15ﾟC in polar solvents. Although tBOS was polymerized at a relatively higher temperature, living polymerization also occurred in the presence of the free ionic species as observed with IBVE.In summary, living cationic polymerization can be achieved in a strongly polar medium, where the dissociated free ionic species is involved in the propagating reaction. This is the first example of living cationic polymerization whose propagating reaction is mediated by free ions. In addition, now that the novel reaction conditions have been developed in this study, new types of living polymers would be obtained from a variety of monomers whose living polymerization have not been operable under the reaction conditions reported before. Less

成功的活性阳离子聚合的关键是为特定的增长端明智地选择合适的阳离子聚合物。也就是说，适当的亲核性阳离子稳定增长端，导致活性阳离子聚合。为了概括活性阳离子聚合的原理，我们研究了在极性溶剂中进行活性阳离子聚合的可行性，其中游离离子物种可能参与其中。异丁基乙烯基醚（IBVE）的活性聚合。在-78 ℃下，HCI-IBVE加合物（1）/ZnCl_2体系在CH_2Cl_2和EtNO_2/CH_2Cl_2混合溶剂中引发活性聚合，而EtAlCl_2体系引发常规阳离子聚合。在这些极性介质中，这两个系统得到的聚合物具有非常相似的和低的全同立构规整度（内消旋<approximately equal>56%），表明传播反应是由自由离子介导的。因此，无论溶剂极性如何，也不管是否涉及游离离子或离子对，活性阳离子聚合都需要 ...更多信息对叔丁氧基苯乙烯（tBOS）的活性聚合。为了证明自由离子与其它阳离子聚合单体进行活性聚合的可行性，在极性溶剂中，以1/ZnCl_2为引发体系，研究了苯乙烯衍生物中活性较高的tBOS在-15 ℃下的阳离子聚合。虽然tBOS聚合在一个相对较高的温度下，活性聚合也发生在与IBVE观察到的自由离子物种的存在下。总之，活性阳离子聚合可以在强极性介质中实现，其中解离的自由离子物种参与的增长反应。这是活性阳离子聚合的第一个例子，其增长反应由自由离子介导。此外，现在，新的反应条件已经在这项研究中开发，新类型的活性聚合物将获得从各种单体，其活性聚合没有在以前报道的反应条件下进行。少