Visible Light-Controlled Radical Polymerization of Propargyl Methacrylate Activated by a Photoredox Catalyst fac-[Ir(ppy)3]
Visible Light-Controlled Radical Polymerization of Propargyl Methacrylate Activated by a Photoredox Catalyst fac-[Ir(ppy)3]
复制标题
光氧化还原催化剂 fac-[Ir(ppy)(3)] 活化的甲基丙烯酸丙炔酯的可见光控制自由基聚合
DOI：
10.1080/10601325.2015.1063883
复制
发表时间：
2015-09-02
影响因子：
2.5
通讯作者：
Yang, Wantai
中科院分区：
文献类型：
--
作者：
Ma, Wenchao;Chen, Dong;Yang, Wantai
尽管热控自由基聚合(CRP)具有很强的稳定性和灵活性，但制备含乙烯基的可点击聚合物仍然是一个巨大的挑战。本文以溴苯乙酸乙酯为引发剂，Fac-Ir(Ppy)(3)为光氧化还原催化剂，研究了甲基丙烯酸丙醇酯(PGMA)的可见光C反应。通过控制聚合时间，可使单体转化率和多分散指数呈线性增加。特别是在[PgMA]/[Initiator]/[fac-Ir(ppy)(3)]=210:1:0.0285，条件下，在单体转化率为17%时，产物的M-n=8300g/m ol，M-w/M-n=1.24；在单体转化率为50%时，产物的M-n=17100g/m o l，M-w/M-n=1.52。这一结果远好于热激活的铜-ATRP的结果。当MMA/PGMA摩尔比为5：1时，单体转化率为66%时，共聚产物M-n=25300g/mol，M-w/M-n=1.75。FTIR、H-1-核磁共振和C-13-核磁共振谱表明PPgMA没有sp(2)-sp(2)碳-碳键，表明乙烯基是完整的。总而言之，这项技术为制备具有侧基的(Co)聚合物提供了一条通用的途径。
Despite the robustness and flexibility of thermal controlled radical polymerization (CRP), it still remains a big challenge to prepare clickable polymers bearing acetenyl groups. In this paper, visible light CRP of propargyl methacrylate (PgMA) is investigated using ethyl--bromophenylacetate as initiator and fac-Ir(ppy)(3) as a photoredox catalyst. By controlling the polymerization time, a linear increase of M-n with monomer conversion and narrow polydispersity index is achieved. Specifically, with [PgMA]/[Initiator]/[fac-Ir(ppy)(3)]=210:1:0.0285, the products show M-n=8300g/mol and M-w/M-n=1.24 at 17% monomer conversion and Mn=17100g/mol and Mw/Mn=1.52 at 50% monomer conversion. This result is much better than that of thermally activated Cu-ATRP of PgMA. When the ratio of MMA/PgMA is 5:1, the copolymerization product shows M-n=25300g/mol and M-w/M-n=1.75 at 66% monomer conversion. The FTIR, H-1-NMR and C-13-NMR spectra of the PPgMA show no sp(2)-sp(2) carbon-carbon bond, indicating that acetenyl groups are intact. In conclusion, this technology offers a versatile route for the preparation of (co)polymers with pendant alkynyl groups.