Chain-Growth Insertion Polymerization of 1,3-Diethynylbenzene High Internal Phase Emulsions into Reactive π-Conjugated Foams

Abstract

The π-conjugated micro/macroporous polyacetylene-type polyHIPE foams were synthesized for the first time by a chain-growth insertion polymerization of high internal phase emulsions (HIPEs). In the first step, the π-conjugated polyHIPE foams were prepared by polymerization of 1,3-diethynylbenzene HIPEs using [Rh(nbd)acac] complex as a catalyst. The π-conjugated polyHIPE foams consist of ethynylphenyl-substituted polyene main chains which are cross-linked by the 1,3-phenylene linkers. In the second step, the foams were chemically and thermally postmodified by applying the alkyne–azide cycloaddition reaction and the solvent free solid phase hyper-cross-linking at temperature of 280 °C. Thus, obtained polyacetylene-type polyHIPE foams exhibit hierarchically structured micro/macroporous morphology with sizes of the macropores and interconnecting pores of 3.4 ± 0.3 μm (or 4.8 ± 0.8 μm) and 0.96 μm (or 1.1 μm), respectively, wherein a substantial volume of micropores is also found within the macroporous walls as revealed by the calculations from the t-plots. The BET (Brunaer–Emmett–Teller) surface area of up to 110 and 380 m2 g–1 was determined before and after solid phase hyper-cross-linking, respectively.