Five kinds of novel bifunctional bicyclo orthoesters (BOEs) were synthesized and copolymerized with multi-functional carboxylic acids, having plural carboxyl and hydroxyl groups, to develop functional materials usable as non-volatile adhesives. In a solid-state reaction of BOEs with the carboxylic acids, mechanical mixing converted the BOE moiety to a corresponding hydrolyzed form via ring-opening and isomerization reactions. The solid-state reaction, requiring moisture and mechanical stress, was accelerated by the higher reactivity given by the a-hydroxyl group in the acids. Superior adhesive bonding to the Ni-Cr alloyed metal substrate was achieved via a heating process at 150 degrees C, and high average tensile strengths of similar to 80 MPa were obtained by using mixtures of BOEs and (DL)-tartaric acid. This highly adhesive property was achieved not only by polycondensation of BOE-hydrolyzates and the carboxylic acids, but also by polyaddition of BOEs and the carboxylic acids. (c) 2006 Elsevier Ltd. All rights reserved.