Abstract3‐Glycidyloxypropyl‐polyhedral oligomeric silsesquioxanes (G‐POSS) was prepared from 3‐glycidyloxypropyl‐trimethoxysilane (GTMS) by hydrolytic condensation. The cocuring behavior and kinetics of G‐POSS with bisphenol‐A epoxy resin (BPAER) using 3‐methyl‐tetrahydrophthalic anhydride (MeTHPA) as curing agent were investigated by nonisothermal differential scanning calorimetry (DSC) and torsional braid analysis (TBA). The face distribution of silicon in the cured products was characterized by energy dispersive X‐ray spectrometry (EDS). The results show that the compatibility of G‐POSS with BPAER is very well and can cocure. The curing mechanism was proposed. The relationship of Ea and conversion α can be obtained by the isoconversional method of Kissinger. These curing reactions can be described by the Šesták–Berggren (S–B) equation and can be depicted by the following equation: $ \font\abc=cmmib10\def\bi#1{\hbox{\abc #1}}{\bi d\alpha \over \bi dt} {=} A\ {\bf exp} (-{E_a \over RT}) {{\alpha}}^m ({\bf 1}-a)^n $. TBA analysis indicated that Tg was decreased when the contents of G‐POSS is over to 30 wt%. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

No abstract

The curing reaction and kinetics of o‐cresol formaldehyde epoxy resin (o‐CFER) with polyhedral oligomeric silsesquioxane of N‐aminoethyl‐γ‐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 Šesták‐Berggren (S‐B) autocatalytic model. The glass transition temperature (Tg) increases with the increase in AEAP‐POSS content, and reaches the maximum, 107°C, when the molar ratio (Ns) 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 2.84 MPa and 143.25 kJ m−2, respectively, when Ns is 0.5. The dielectric constant (ε), dielectric loss factor (tan δ), volume resistivity (ρv), and surface resistivity (ρs) are 4.98, 3.11 × 10−4, 3.17 × 1012 Ω cm3, and 1.41 × 1012 Ω cm2, respectively, similarly at Ns 0.5. Copyright © 2009 John Wiley & Sons, Ltd.

No abstract