New poly(ether‐ester) thermosets obtained by cationic curing of DGEBA and 7,7‐dimethyl‐6,8‐dioxaspiro[3.5] nonane‐5,9‐dione with several Lewis acids as initiators |
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| Authors: | Lidia González Xavier Ramis Josep Maria Salla Ana Mantecón Angels Serra |
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| Institution: | 1. Departament de Química Analítica i Química Orgànica, Universitat Rovira i Virgili. C/Marcel·lí Domingo s/n, 43007 Tarragona, Spain;2. Laboratori de Termodinàmica, ETSEIB. Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona, Spain |
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| Abstract: | Scandium, ytterbium, and lanthanum triflates and boron trifluoride monoethylamine were used as cationic initiators to cure a mixture 2:1 (mol/mol) of diglycidylether of bisphenol A (DGEBA) and 7,7‐dimethyl‐6,8‐dioxaspiro3.5]nonane‐5,9‐dione (MCB). The evolution of the epoxy and lactone during curing and the linear ester groups in the final materials were evaluated by Fourier Transform Infrared in the attenuated‐total‐reflection mode. The kinetic parameters of the curing process were calculated from DSC analysis applying isoconversional procedures. The shrinkage on curing and the thermal degradability of the materials on varying the initiator used were evaluated. The expandable character of MCB was confirmed. The materials obtained were more degradable than conventional epoxy resins due to the tertiary ester groups incorporated in the network by copolymerization. © 2008 Wiley Periodicals, Inc J Polym Sci Part A: Polym Chem 46: 1229–1239, 2008 |
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| Keywords: | cationic polymerization crosslinking epoxy resins lactones ROMP thermosets |
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