Collier, Harvest L.
Epoxides are known to form ring-opened polymer products that have demonstrated improved material strength, high heat stability, and chemical resistance as adhesives, coatings, and molding materials. It has been suggested that imidazoles can be used in the catalysis of this polymerization, and that the pyridyl nitrogen of the imidazole ring participates in epoxy ring-opening and is then incorporated in the polymeric structure. This study was conducted to test this theory of the role of pyridyl nitrogen in the reaction of 1,1'-dihydroxyethyl-2,2'- biimidazole (HEB) and metal-HEB complexes with the diglycidyl ether of bisphenol A (DGEBA). Of particular interest in this study is that HEB also exhibits two alcohol functionalities which are known to induce epoxy ringopening and that HEB also forms an alkoxide ion adduct which promotes chain growth. DSC and IR were used to monitor the reactions of HEB and its metal complexes with DGEBA. These studies support the conjecture that the pyridyl nitrogen participates in epoxide ring-opening. They also suggest that the pyridyl nitrogen ring-opening is the first reaction, followed by the formation of the alkoxide adduct formation and the hydroxyethyl group etherification. NMR and GPC were employed to further characterize the polymer formed. NMR results varified the proposed polymer structure, and molecular weight determination by GPC showed a high molecular weight, highly cross-linked polymer product.
16 Apr 1992
Proctor, R. A., "The Synthesis and Characterization of Metal Binding Polymers Containing 2,2'-Biimidazole" (1992). Opportunities for Undergraduate Research Experience Program (OURE). 69.