The thermal degradation in vacuo of an amine‐cured epoxide resin

Abstract

Abstract The degradation in vacuo of the cured resin from stoichiometric amounts of the diglycidyl ether of bisphenol A and p,p′ ‐diaminodiphenylmethane was studied at temperatures of 303.7 and 304.0 ± 0.2°C. The condensible products of the degradation at these temperatures were collected and the major components were isolated as pure compounds. These were identified as water, bisphenol A, 2‐(benzofur‐5‐yl)‐2‐( p ‐hydroxyphenyl)propane, N,N,N′,N′‐tetramethyl‐ p,p′ ‐diaminodiphenylmethane, phenol, p ‐isopropylphenol, p ‐isopropenylphenol, N,N‐dimethylaniline, N‐methylaniline, N,N‐dimethyl‐ p ‐toluidine, benzofuran, and N‐methyl‐ p ‐toluidine. The presence of 2,2‐bis(benzofur‐5‐yl)propane was suspected. The gaseous degradation products were identified as acetaldehyde, chloromethane, carbon dioxide, carbon monoxide, methane, ethane, ethene, and nitrogen. Tentative reaction mechanisms are proposed to account for the formation of the products identified. The possible nature of some of the minor degradation products is discussed. The results are related to those of previous studies of the degradation of the same and similar resin–hardener systems.