Regio-regular poly(thienylene vinylene)s (rr-PTVs) through acyclic diene metathesis (ADMET) polymerization and the impact of alkyl side-chains on polymer molecular weight and solubility
Regio-regular poly(thienylene vinylene)s (rr-PTVs) through acyclic diene metathesis (ADMET) polymerization and the impact of alkyl side-chains on polymer molecular weight and solubility
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DOI：
10.1016/j.polymer.2021.124150
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发表时间：
2021-09
期刊：
影响因子：
4.6
通讯作者：
Yousef M. Katba-Bader;Lingyao Meng;C. Guan;Yang Qin
中科院分区：
文献类型：
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作者：
Yousef M. Katba-Bader;Lingyao Meng;C. Guan;Yang Qin
聚亚硫乙烯(PTV)是目前研究较少的一种典型的共轭聚合物。在PTV结构中每一对相邻的噻吩基单元之间插入一个小的双键可能会使噻吩环直接官能化，这可以微调聚合物的电子性质，而不会显著影响主链的平面性。然而，导致这种量身定做的PTV的合成方法很少。在本文中，我们报道了一种新的合成策略，即在每个噻吩基上生成一系列含有溴原子和不同烷基侧链的区域规则(Rr)PTV。该方法从合成定义明确的二聚单体开始，这些单体在admet聚合时导致rr-PTV。用核磁共振和吸收光谱对单体和聚合物进行了充分的表征。我们发现，直链和微支化的烷基链在聚合过程中会导致沉淀，从而由于聚合物的溶解度有限而导致较低的表观相对分子质量，而长支化和大体积的硅烷基醚链导致PTV具有更大的溶解度和更高的分子量。
Poly(thienylene vinylene) (PTV) is one of the prototypical conjugated polymers (CPs) that has received relatively little attention. The insertion of one small double bond between every pair of adjacent thiophene units in PTV structures potentially allow direct functionalization of the thienyl rings, which can fine-tune polymer electronic properties without significantly impact main-chain planarity. However, synthetic methods leading to such tailor-designed PTVs are scarce. In this paper, we report a new synthetic strategy that produces a series of regio-regular (rr) PTVs bearing bromine atoms and different alkyl side-chains on every thiophene unit. The methodology starts with synthesis of well-defined dimeric monomers that lead to rr-PTVs upon ADMET polymerization. The monomers and polymers are fully characterized by NMR and absorption spectroscopy. We found that linear and slightly branched alkyl chains led to precipitation during the polymerization process and thus low apparent molecular weight due to limited polymer solubility, while long-branched and bulky silyl-alkyl ether chains led to PTVs with greater solubility and higher molecular weights.