Abstract
Two types of chemical analysis were successfully applied to determine three functional groups in the epoxides cured with carboxylic acid.
The functional group in the cured epoxides is difficult to analize by the known methods because the cured epoxides are insoluble in organic solvents. Therefore, the cured epoxides should be pretreated by freeze milling and swelling with tetrahydrofuran. Two methods of chemical analysis with a potentiometric titration were proposed. The first one is the hydrochloric acid-tetrahydrofuran method, effective for simultaneous determination of the epoxide and carboxyl groups in the cured epoxides, and another is the acetyl bromide method, also effective for simultaneous determination of the epoxide and hydroxyl groups in the cured epoxides. The relative standard deviations were 2.6-4.4% for epoxide group, 2.5% for carboxyl group and 5.5% for hydroxyl group, respectively.
The determination of three functional groups in the cured epoxides by these methods have made possible to estimate a curing mechanism of epoxides with carboxylic acid.
