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Poly(ethylene-co-methacrylic acid) (EMAA) as an efficient healing agent for high performance epoxy networks using diglycidyl ether of bisphenol A (DGEBA)

journal contribution
posted on 01.06.2016, 00:00 authored by K Pingkarawat, C Dell'Olio, Russell VarleyRussell Varley, A P Mouritz
The use of poly(ethylene-co-methacrylic acid) (EMAA) as an efficient and repeatable thermally activated healing agent in a high performance diglycidyl ether of bis phenol A (DGEBA)/diethyl toluene diamine (DETDA) mendable epoxy composite is presented. Despite curing above the melting point of EMAA (Tm = 85 °C), healing was facilitated by incorporating a preliminary low temperature curing step of 5 h at 80 °C, prior to epoxy cure at 150 °C. Healing was subsequently shown to occur at 130 °C, 150 °C and 200 °C via a pressure delivery mechanism derived from a condensation reaction between EMAA and the residual hydroxyl groups formed during epoxy cure. Healing was repeatable over 5 healing cycles despite a gradual reduction in efficiency, while efficiency increased with increasing healing temperature. Importantly, healing was evident at 130 °C, despite the epoxy network remaining in the glassy state at this temperature (Tg = 150-158 °C). As well as creating high performance mendable composites based upon DGEBA/DETDA, EMAA particles distributed evenly on the surface of the crack plane were found to enhance mode I interlaminar fracture toughness by up to 200% for both DETDA and 4,4 diamino diphenyl sulphone (44 DDS) systems.

History

Journal

Polymer

Volume

92

Pagination

153 - 163

Publisher

Elsevier

Location

Amsterdam, The Netherlands

ISSN

0032-3861

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2016, Elsevier Ltd.