The effect of bismaleimide resin on curing kinetics of epoxy-amine thermosets

Synthesis, characterization, and shape-memory performances of monoamine-toughened epoxy resin

Epoxy resins were toughened by octylamine, dodecylamine, and hexadecylamine, respectively. The curing temperature and the curing kinetics were studied by non-isothermal differential scanning calorimetry (DSC) to optimize the cure conditions. The mass ratios of the monoamine to the total mass of triethylenetetramine and monoamine were varied to obtain polymers with different compositions. The cured polymers were analyzed by DSC, scanning electron microscopy (SEM), and mechanical analyses. Shape-memory performance was evaluated by fold-deploy tests. The glass transition temperature ( Tg) decreased with increasing carbon numbers of monoamine, and the decrease in Tg scaled with the content of monoamines added in the system. The elongation increased with an increase in monoamine content and alkyl chain length. The better toughness of the monoamine-rich system was further confirmed by the results of SEM. The strain fixity ratio increased with a decrease in monoamine content. The strain recovery ratios of all systems were greater than 98%.

Synthesis, Characterization and Thermal Degradation Study of Terpolymer-derived from p-Hydroxybenzoic Acid, Diaminonaphthelein with Formaldehyde

Resin pHDNF has been synthesized by the condensation of p-hydroxybenzoic acid and diaminonaphthelein with formaldehyde in the presence of catalyst hydrochloric acid in 1 : 1 : 2 molar proportions of reactants. The purity of newly synthesized terpolymer has been tested and confirmed by the thin layer chromatography (TLC) technique. Detailed thermal degradation studies of the pHDNF resin have been carried out to ascertain its thermal stability. The thermal degradation curve was examined in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change and apparent energy change. The Freeman—Carroll and Sharp—Wentworth methods were applied for the calculation of kinetic parameters and the data from the Freeman—Carroll method was been used to determine various thermodynamic parameters. The terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and UV-visible spectral studies. The number-average molecular weight of the resin was determined by non-aqueous conductometric titration.