Epoxy Curing Agents, II. Deactivated Imidazoles and Flexible Systems
Abstract
Imidazole-type compounds will cure epoxy adhesives under moderate conditions and impart a relatively high heat resistance to the product. Various means of increasing the pot life to permit extended storage prior to use were studied. These included deactivation of the imidazole ring with chloro, nitro, and cyano groups which rendered the catalyst inactive toward epoxy resins, microencapsulation of imidazoles, also unsuccessful, and use of imidazole salts which yielded a heat-resistant adhesive but required high curing temperatures. The mechanisms of imidazole curing of two flexible epoxy systems, on a polyesterurethane elastomer system, and the other a polysulfide rubber system, were studied by means of infrared and nuclear magnetic resonance spectroscopy. A novel side reaction involving the imidazole catalyst in the polysulfide rubber system is discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1971
- Accession Number
- AD0729300
Entities
People
- Thomas J. Dearlove
Organizations
- Harry Diamond Laboratories