{'fraction_non_alphanumeric': 0.012753188297074268, 'fraction_numerical': 0.0037509377344336083, 'mean_word_length': 5.603960396039604, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Rheological and Calorimetric Characterization of an Epoxy System Cured in Presence of a Reactive Polyethersulphone

Curing and gelation of tetraglycidyl-4,4'-diaminodiphenyl methane epoxy resin (MY 720) in the presence of an amine functionalized thermoplastic PES was studied by dynamic rheological and calorimetric measurements. The gel point was determined rheologically and the apparent activation energy of the curing reaction was determined by means of both rheology and differential scanning calorimetry. By the dynamic rheological measurements under isothermal conditions the gel time was found to vary with the curing temperature and the composition of the system. It was found that the amine functionalized thermoplastic PES works as a curing agent for the epoxy resin but the reaction is less pronounced and the apparent activation energy higher than that of the control system. However, using the amine functionalized thermoplastic PES together with the conventional DDS curing agent, a synergistic effect is observed as a result of the greater number of activated molecules responsible for the crosslinking reaction. Moreover, in order to analyze the microstructure-properties relationship in the modified epoxy systems, SEM observation was carried out on the fracture surfaces of the reactive PES containing epoxy resin.