Volume 16, Issue 5, 2007, Pages 167-172

LETTER: A NOVEL SELF-HEALING EPOXY SYSTEM WITH MICROENCAPSULATED EPOXY AND IMIDAZOLE CURING AGENT

Min Zhi Rong^1,2*, Ming Qiu Zhang², Wei Zhang¹

¹ Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, OFCM Institute, School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510275, P. R. China
² Materials Science Institute, Zhongshan University, Guangzhou 510275, P. R. China

*Author to whom correspondence should be addressed, E-mail address: cesrmz@mail.sysu.edu.cn

Received 7 June 2007; accepted 23 October 2007

ABSTRACT

This work reported a novel epoxy system that can perform a self-repairing operation against cracks at elevated temperature. For this purpose, a two-component healing agent consisting of microencapsulated epoxy and imidazole was pre-embedded into epoxy matrix. The microencapsulated epoxy was self-synthesized in advance using poly(urea-formaldehyde) as the wall material through a two-step polymerization approach in an oil-in-water emulsion. The performance of the self-healing epoxy composite was evaluated by fracture toughness measurement. It was found that the self-healing epoxy containing 20wt.% healing agent received a healing efficiency of 106% at the optimum capsulated imidazole-to-epoxy weight ratio of 0.2.

Keywords: Smart materials; Matrix cracking; Epoxy; Self-healing