Dynamics and thermal properties of epoxy resin cured by new diamino disiloxanes

ABSTRACT Two disiloxane compounds, 3,3′‐(1,3‐dimethyl‐1,3‐diphenyl‐1,3‐disiloxanediyl)bis(benzenamine) (C1) and 4,4′‐(1,3‐dimethyl‐1,3‐diphenyl‐1,3‐disiloxanediyl)bis(benzenamine) (C2) were synthesized and used as new curing agents of DGEBA epoxy resin with an epoxy value of 0.51 (E‐51). The curing kinetics of E‐51/C1 and E‐51/C2 systems was investigated by non‐isothermal differential scanning calorimetry (DSC) analyses. The activation energy (ΔE) and the characteristic cure temperatures of the two systems were determined. The two systems have the similar activation energy. The reactivity of E‐51/C1 is higher than that of E‐51/C2. The reaction orders of E‐51/C1 and E‐51/C2 are 0.88 and 0.87, respectively, illustrating that curing reaction between the epoxy resin and curing agent (C1 or C2) is complicated. The DSC result shows that E51 cured by C2 has higher Tg; whereas thermogravimetric analysis results indicate that E51 cured by C1 has higher thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42385.