Kinetic heterogeneity of epoxide oligomers

Peculiarities of the structure and properties of highly cross-linked polymer networks

“…A comparison of the results obtained by pulse NMR with those of viscosimetric and dielectric studies has shown that the free volume of the system mainly affects the nature of the temperature dependence of relaxation parameters. NMR cross-relaxation, differential microcalorimetry, and IR spectroscopic studies of the process of structure formation of a polymer based on bisphenol A diglycidyl ether and 1,3-bis(aminomethyl)adaman-tane have shown 18 that native specimens possess an ensemble of slowly relaxing protons with a glass transition temperature 20 K higher than that of a fully cured polymer. The temperature of freeing the mobility of the structural elements of native and fully cured polymers decreases as the temperature of isothermal curing increases.…”

“…, where a is the degree of cross-linking, which characterises the portion of phenyl groups involved in cross-links and is equal to 1/m. Substituting the values of all the network parameters into Eqn (18), we get…”