Fundamental Studies and Recent Advances in Anionic Polymerization 3. Molecular Design of Elastomers by Means of Living Anionic Polymerization
Fundamental Studies and Recent Advances in Anionic Polymerization 3. Molecular Design of Elastomers by Means of Living Anionic Polymerization
复制标题
阴离子聚合的基础研究和最新进展3.活性阴离子聚合弹性体的分子设计
DOI：
10.2324/gomu.80.59
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
A. Hirao
中科院分区：
文献类型：
--
作者：
K. Sugiyama;A. Hirao
本文综述了以丁二烯、异戊二烯等1，3-二烯单体为原料，通过活性阴离子聚合合成弹性体的各种分子设计方法。通过适当选择引发剂、溶剂、温度、浓度和添加剂等聚合变量，可以得到各种链长精确可控、微观结构良好的聚（1，3-丁二烯）和聚（异戊二烯）。此外，苯乙烯-1，3-丁二烯橡胶（SBR）和苯乙烯-1，3-丁二烯-异戊二烯橡胶（SBIR）的无规共聚物以及聚苯乙烯-嵌段-聚-1，3-丁二烯-嵌段-聚苯乙烯（SBS）和聚苯乙烯-嵌段-聚异戊二烯-嵌段-聚苯乙烯（SIS）的阿坝三嵌段共聚物目前已经工业化生产。后一种嵌段共聚物是众所周知的热塑性弹性体，其中每个链段在分子水平上是相分离和自组织的，并且聚苯乙烯链段自组织作为物理交联点起作用。通过活性阴离子聚合合成了两个链端均带有羟基（每个链端一个羟基）的端部官能化的聚1，3-丁二烯和聚异戊二烯，并将其用作模型网络弹性体。已经发现，在合成弹性体中引入极性官能团如氨基和羟基可以显著影响其物理性能。我们最近建立了一种新的方法，基于活性阴离子聚合使用专门设计的1，1-二苯基乙烯衍生物，通过该多官能化是可能的聚合物链端和/或链内。我们还展示了新的合成弹性体的几种可能性，如链端多官能化的聚-1，3-二烯，由聚-1，3-二烯链段组成的规则和不对称星形支化聚合物，以及苯乙烯和1，3-二烯单体的星形支化嵌段共聚物，所有这些都可以通过上述方法合成。
This paper will review various molecular designs and syntheses of synthetic elastomers by means of living anionic polymerization of 1, 3-diene monomers such as 1, 3-butadiene and isoprene. By appropriately choosing polymerization variables such as initiator, solvent, temperature, concentration, and additive, a wide variety of poly(1, 3-butadiene)s and poly(isoprene)s with precisely controlled chain-lengths as well as desired microstructures have been available. Furthermore, random copolymers of styrene-1, 3-butadiene rubber (SBR) and styrene-1, 3-butadiene-isoprene rubber (SBIR) and ABA triblock copolymers of polystyrene-block-poly-1, 3-butadiene-block-polystyrene (SBS) and polystyrene-block-polyisoprene-block-polystyrene (SIS) have been industrially produced at the present time. The latter block copolymers are well known as thermoplastic elastomers where each segments are phase-separated and self-organized at molecular level and the polystyrene segments self-organized work as physically cross-linked points. Well-defined chain-end-functionalized poly-1, 3-butadiene and polyisoprene with hydroxyl groups at both chain-ends (one hydroxyl group per each chain-end) are synthesized by living anionic polymerization and used as model network elastomers. It has been found that the introduction of polar functional groups such as amino and hydroxyl groups into synthetic elastomers can affect significantly on their physical properties. We have recently established a novel methodology based on living anionic polymerization using specially designed 1, 1-diphenylethylene derivatives, by which multi-functionalization is possible at polymer chain-ends and/or in-chains. We have also demonstrated several possibilities of new synthetic elastomers such as chain-end-multi-functionalized poly-1, 3-dienes, regular and asymmetric star-branched polymers comprised of poly-1, 3-diene segments, and star-branched block copolymers of styrene and 1, 3-diene monomer, all of which can be synthesized by the above-mentioned methodology.