Development of Multipurpose Capsular Adhesive Systems

摘要

A unique, polyester-epoxy adhesive system was developed which cures very rapidly upon mixing of its two components and adheres to a multitude of substrates under various environmental conditions. Each of the two liquid adhesive components can be encapsulated to form 'pseudo solids'. Mixing together of the two capsular components into the proper ratio forms a stable, 'one can,' dry powder adhesive that is easily activated upon rupture of the capsules. This rapid curing capsular adhesive system, with its improved stability, handling and logistics characteristics due to encapsulation, was further characterized during the second phase of the program. Capsular adhesive stability was found to be nine months under laboratory conditions with the epoxy component being the limiting factor. Several formulation variations were made that affected cure time, bond strength and adhesion properties. Encapsulation of each of the two components was easily scaled up through the pilot-plant stage. Several mechanical adhesive applicator designs were developed and evaluated for the extrusion and application of both the capsular adhesives and the same formulations in their liquid, unencapsulated forms. (Author)