Chain-Growth Insertion Polymerization of 1,3-Diethynylbenzene High Internal Phase Emulsions into Reactive π - Conjugated Foams
Abstrakt
The π-conjugated micro/macroporous polyacetylene-type polyHIPE foams were synthesized for the fi rst 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 alkyneMINUS SIGN azide cycloaddition reaction and the solvent free solid phase hyper-cross-linking at temperature of 280oC.
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 MINUS SIGN Emmett MINUS SIGN Teller) surface area of up to 110 and 380 m2g MINUS SIGN 1 was determined before and after solid phase hyper-cross-linking, respectively.