Novel silicone aliphatic amine curing agent for epoxy resin: 1,3-Bis(2-aminoethylaminomethyl) tetramethyldisiloxane. 2. Isothermal cure, and dynamic mechanical property

A multifunctional silicone-contained aliphatic polyamine, 1,3-bis(2-aminoethylaminomethyl) tetramethyldisiloxane (SFA), was originally employed to cure bisphenol A epoxy resin (DGEBA) isothermally, and the curing reaction of DGEBA–SFA was systematically investigated by DSC measurement at 55, 60, 65 and 70 °C. The model fitting kinetic analysis confirmed that the reaction rate could be well simulated with an autocatalytic Kamal model up to the onset of the diffusion control stage. Taking the diffusion effects into account, the extended Kamal model was applied to fit the experimental reaction rate, with an excellent agreement throughout whole reaction process. The multi-frequency dynamic mechanical analysis shows that the cured DGEBA–SFA appears in a β relaxation in low temperature and an α relaxation in higher temperature interval (>80 °C). The relaxation activation energies for α and β relaxations are 70.1 and 287.6 kJ/mol, respectively.