Multiple-SO3H functioned ionic liquid as efficient curing agent for phthalonitrile-terminated poly(phthalazinone ether nitrile)

Combined with the advantages of low melting point, high thermal stability and strong acidity, a multiple-SO3H functioned ionic liquid (MIL) was developed successfully as a curing agent to promote the curing reaction of phthalonitrile-terminated poly(phthalazinone ether nitrile) (PPEN-Ph). The curing kinetics over differential scanning calorimetry (DSC) showed that both the initial curing temperature T-po' and apparent activation energy Ea' (based on Kissinger equation) were reduced significantly over MIL (207.9 degrees C and 101.5 kJ/mol) compared to the common curing agent ZnCl2 (268.5 degrees C and 201.5 kJ/mol). Moreover, under identical curing conditions, the resulting thermosetting resin over former (T-d5%= 526.1 degrees C) showed better thermal stability than that over latter (T-d5%= 512.1 degrees C). These results indicated that MIL should be a good candidate as a curing agent for phthalonitrile resins. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.