Covalently crosslinked 1,2,4-triazolium-containing polyester networks prepared by Michael addition polymerization

Michael addition polymerization was used to generate a series of 1,2,4-triazolium-based covalently crosslinked polyester networks. Within the series, the acetoacetate to acrylate ratio as well as the counteranion were varied in an attempt to correlate structural changes with the thermal and mechanical properties of the corresponding networks. An increase in acrylate concentration, as expected, led to an increase in the apparent crosslink density rho(x) as well as glass transition temperature (T-g), thermal stability(T-d5%) and rubbery plateau storage modulus (E'). Use of larger, non-coordinating anions such as triflate [OTf] and bis(trifluoromethylsulfonyl) imide [NTf2] led to a decrease in T-g and E' but an increase in the thermal stability (T-d5% > 295 degrees C). Overall, the thermal and mechanical properties of the 1,2,4-triazolium-containing network, at an acrylate to acetoacetate ratio of 1.4:1.0, were found to be on par with the analogous imidazolium-based network. (C) 2015 Elsevier Ltd. All rights reserved.