Versatile catalytic strategy for polar-functionalized, cross-linkable, self-healing, and photo-responsive polyolefins
Versatile catalytic strategy for polar-functionalized, cross-linkable, self-healing, and photo-responsive polyolefins
复制标题
用于极性功能化、可交联、自修复和光响应聚烯烃的多功能催化策略
DOI：
10.1016/j.scib.2020.01.010
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发表时间：
2020
期刊：
影响因子：
18.9
通讯作者：
Marks, Tobin J.
中科院分区：
文献类型：
--
作者：
Gao, Yanshan;Marks, Tobin J.
聚烯烃是世界范围内应用最广泛的聚合物材料，其主要原料是丰富的、低成本的乙烯和丙烯。广泛的聚烯烃应用范围部分归因于仅烷烃CAC和CAH键网络的化学惰性/稳定性。然而，当考虑到需要粘附性、韧性、表面活性、与其他材料的相容性、可染性、阻隔性、用于静电抑制的导电性和有利的流变性的其他重要应用时，这种有利的属性成为限制[1-4]。虽然过去已使用聚合后官能化来增强聚烯烃性能[1]，但此类改性通常需要苛刻的条件，缺乏选择性，并且可能引起副反应，例如断链和/或交联[3]。因此，在初始聚合过程中向聚烯烃中引入极性官能团已成为原子经济的“圣杯”和当今烯烃聚合研究的中心焦点。在制备极性聚烯烃材料时，工业上成功的早期过渡金属催化仅取得有限的成功，主要是由于高催化剂亲氧性/刘易斯酸性和典型的极性共聚单体刘易斯碱性[5-7]。相比之下，后过渡金属（Ni，Pd）催化剂表现出大得多的极性共聚单体耐受性[1，2，8]，这使得能够与各种极性共聚单体共聚。然而，由于相对低的聚合活性和低的产物分子量，现实世界的应用潜力仍然是一个挑战。因此，开发新的催化剂体系和聚合方法，为早期和后期过渡金属，是一个激烈的研究焦点的话题。虽然以低成本开发有效的催化体系是一个重大挑战，但另一个重要问题涉及哪种极性聚烯烃可以提供所需的性能以满足市场/客户需求。关于通过Ni/Pd催化[1，2，8]可获得的广泛极性聚烯烃的相关研究[9]很少。因此，这些新开发的极性聚烯烃的性能研究处于初始阶段并且受到限制。最近，中国科学技术大学陈长乐教授的小组[10]报道了高效合成
Polyolefins are the most widely used polymeric materials worldwide, with abundant, low cost ethylene and propylene as the principal feedstocks. The broad polyolefins applications scope is in part due to the chemical inertness/stability of the exclusively alkane CAC and CAH bond networks. However, this advantageous attribute becomes a limitation when considering other important applications requiring adhesion, toughness, surface activity, compatibility with other materials, dyeability, barrier properties, electrical conductivity for static electricity suppression, and favorable rheological properties [1–4]. While post-polymerization functionalization has been used in the past to enhance polyolefin performance [1], such modifications typically require harsh conditions, lack selectivity, and may induce side reactions such as chain scission and/or cross-linking [3]. Thus, introducing polar functional groups into polyolefins during the initial polymerization process has become an atom-economical ‘‘holy grail” and a central focus of olefin polymerization research today. In creating polar polyolefin materials, industrially successful early transition metal catalysis has only achieved limited success, mainly due to high catalyst oxophilicity/Lewis acidity and typical polar comonomer Lewis basicity [5–7]. In contrast, late transition metal (Ni, Pd) catalysts exhibit far greater polar comonomer tolerance [1, 2, 8], which enables copolymerizations with a variety of polar comonomers. However, due to the relatively low polymerization activity and low product molecular weight, the real-world applications potential remains a challenge. Thus, developing new catalyst systems and polymerization methodologies, for both early and late transition metals, is a topic of intense research focus. While developing efficient catalytic systems at a low cost is a significant challenge, another important question concerns which polar polyolefins might deliver desirable performance to satisfy market/customer needs. There are only few relevant studies [9] on the wide range of polar polyolefins available via Ni/Pd catalysis [1, 2, 8]. Thus, performance studies of these newly developed polar polyolefins are at the initial stage and limited. Recently, Prof. Changle Chen’s group [10] at the University of Science and Technology of China reported the efficient synthesis