Hyperbranched polymers with step-growth chemistries from transfer-dominated branching radical telomerisation (TBRT) of divinyl monomers
Hyperbranched polymers with step-growth chemistries from transfer-dominated branching radical telomerisation (TBRT) of divinyl monomers
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DOI：
10.1039/d0py01309a
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发表时间：
2020-12-28
影响因子：
4.6
通讯作者：
Rannard, Steve P.
中科院分区：
文献类型：
--
作者：
Cassin, Savannah R.;Chambon, Pierre;Rannard, Steve P.
聚合物的商业合成通常限于通常被认为是相互排斥的两种主要机制，即逐步增长和链增长聚合。这也定义了大分子合成的大量学术进展，包括越来越多地研究可逆失活自由基聚合技术（链增长）和复杂的聚合物结构，如树枝状聚合物（逐步增长）。我们在这里报告了一种新的合成策略，利用传统的自由基链生长化学，在改性的调聚条件下，形成支化聚合物含有化学品常规形成的逐步增长的条件下。调聚通常限于小分子合成，并且采用跨越底物的不饱和键的加成，同时使底物之间的分子间反应最小化。通过仔细操作反应条件，我们已经创建了一个“转移主导的支化自由基调聚”机制，该机制使用工业相关的自由基链增长化学，从分子量超过1000 kg mol（-1）的多乙烯基单体产生含有逐步增长基序的支化聚合物。这种方法的范围是相当大的，允许获得全新的大分子结构。
The commercial synthesis of polymers is generally limited to two main mechanisms that are typically considered to be mutually exclusive, namely step-growth and chain-growth polymerisation. This also defines the vast number of academic advances in macromolecular synthesis including the increasingly studied reversible deactivation radical polymerisation techniques (chain-growth) and complex polymer architectures such as dendrimers (step-growth). We report here a new synthetic strategy that utilises conventional free radical chain-growth chemistry, under modified telomerisation conditions, to form branched polymers containing chemistries conventionally formed under step-growth conditions. Telomerisation is typically limited to small molecule synthesis and employs addition across the unsaturated bond of a substrate, whilst minimising intermolecular reaction between substrates. Through the careful manipulation of reaction conditions, we have created a 'transfer dominated branching radical telomerisation' mechanism that creates branched polymers containing step-growth motifs from multi-vinyl monomers, with molecular weights in excess of 1000 kg mol(-1), using industrially relevant free radical chain-growth chemistry. The scope of this approach is considerable, allowing access to entirely new macromolecular structures.