Visible light‐induced metal‐free atom transfer radical (co)polymerization of maleimides using commercial organocatalysts

Abstract

AbstractMetal‐free photocontrolled atom transfer radical polymerization (ATRP) has recently received increasing attention due to its ability to avoid heavy metal contamination. However, the polymerization of 1,2‐disubstituted olefin monomers by photocontrolled ATRP has rarely been reported. In this contribution, visible light‐induced metal free atom transfer radical (co)polymerization of maleimides (MI) by using several commercial organocatalysts was investigated in both batch and continuous flow processes. It was shown that the combination of the commercial dye eosin Y (EY) and cocatalyst N,N′,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) can mediate controlled and selective ATRP of various N‐alkyl substituted MI monomers. The effect of polymerization time, initiators and catalysts are discussed. The results revealed that molecular weight (Mn) of the obtained polymers was increased by increase in monomers conversion with their narrow polydispersities (PDI ≤1.2). MIs alternating copolymerization with styrenes (St) under irradiation of visible light was also done which generated the polymaleimide resins with ultrahigh glass transition temperatures (Tg up to 259°C). Moreover, continuous flow process was also used for the co‐polymerization of MI and St by using a tubular reactor to get polymaleimide resins. Thus, this work provides an effective strategy to obtain copolymers of MI monomers and styrenes via both batch and continuous flow processes, enabling technical advantages for potential large‐scale applications.