Curing kinetics, thermal, mechanical, and dielectric properties based on o-cresol formaldehyde epoxy resin with polyhedral oligomeric (N-aminoethyl-γ-amino propyl)silsesquioxane

The curing reaction and kinetics of o-cresol formaldehyde epoxy resin (o-CFER) with polyhedral oligomeric silsesquioxane of N-aminoethyl-gamma-amino propyl group (AEAP-POSS) were investigated by differential scanning calorimetry (DSC). The thermal, mechanical, and dielectric properties of o-CFER/AEAP-POSS nanocomposites were investigated with thermogravimetric analysis (TGA), torsional braid analysis (TBA), tensile tester, impact tester, and electric analyzer, respectively. The results show that the activation energy (E) of curing reaction is 58.08 kJ/mol, and the curing reaction well followed the Sestak-Berggren (S-B) autocatalytic model. The glass transition temperature (T(g)) increases with the increase in AEAP-POSS content, and reaches the maximum, 107 degrees C, when the molar ratio (N(s)) of amino group to epoxy group is 0.5. The nanocomposites containing a higher percentage of AEAP-POSS exhibited a higher thermostability. The AEAP-POSS can effectively increase the mechanical properties of epoxy resin, and the tensile and impact strengths are 2.84MPa and 143.25 kJ m(-2), respectively, when N(s) is 0.5. The dielectric constant (epsilon), dielectric loss factor (tan delta), volume resistivity (rho(v)), and surface resistivity (rho(s)) are 4.98, 3.11x10(-4), 3.17x10(12) Omega cm(3), and 1.41x10(12) Omega cm(2), respectively, similarly at N(s) 0.5. Copyright (C) 2009 John Wiley & Sons, Ltd.