Synthesis of All-Conjugated Donor鈥揂cceptor鈥揇onor ABA-Type Triblock Copolymers via Kumada Catalyst-Transfer Polycondensation

详细信息    查看全文

• 作者：Jin Wang ; Mitsuru Ueda ; Tomoya Higashihara
• 刊名：ACS Macro Letters
• 出版年：2013
• 出版时间：June 18, 2013
• 年：2013
• 卷：2
• 期：6
• 页码：506-510
• 全文大小：272K
• 年卷期：v.2,no.6(June 18, 2013)
• ISSN：2161-1653

文摘

A novel initiator, N,N鈥?/i>-bis(2-decyltetradecyl)-2,6-dibromonaphthalene-1,4,5,8-bis(dicarboximide) (NDI-Br₂), was found effective in the Kumada catalyst-transfer polycondensation (KCTP) for the synthesis of regioregular poly(3-hexylthiophene) (P3HT). In addition, a two-step method of synthesizing all-conjugated triblock copolymers comprised of both n-type and p-type blocks was proposed. With a 10:9 feed molar ratio of NDI-Br₂ to 2,5-bis(trimethylstannyl)thiophene, an n-type macroinitiator (PNDITh-Br₂) was prepared via the Stille coupling reaction. Two outer P3HT blocks were then emanated via KCTP initiated by PNDITh-Br₂ to produce all-conjugated ABA-type triblock copolymers. The size exclusion chromatography (SEC) curves of all the triblock copolymers showed narrow distribution, with the lowest polydispersity index (PDI) of 1.15. Moreover, the molecular weight of the block copolymer was found to be independent of the amount of Ni catalyst, while it can be tailored by the feed molar ratio of the thiophene monomer to PNDITh-Br₂. The transmission electron microscopy (TEM) images and grazing-incidence wide-angle X-ray scattering (GIWAXS) patterns of the block copolymer thin film revealed a well-defined lamellar structure and two distinguished crystalline domains, where the P3HT layer was in the range of 10鈥?0 nm and presented an edge-on rich alignment.