Curing behavior and thermal properties of multifunctional epoxy resin with methylhexahydrophthalic anhydride

Abstract

ABSTRACT:The curing behavior and thermal properties of bisphenol A type novolac epoxy resin (bisANER) with methylhexahydrophthalic anhydride (MHHPA) at an anhydride/epoxy group ratio of 0.85 was studied with Fouriertransform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetry. The results showed that the FTIR absorption intensity of anhydride and epoxide decreased during the curing reaction, and the absorption peak of ester appeared. The dynamic curing energies were determined as 48.5 and 54.1 kJ/mol with Kissinger and Flynn-Wall-Ozawa methods, respectively. DSC measurements showed that as higher is the curing temperature, higher is the glass transition. The thermal degradation of the cured bisANER/MHHPA network was identified as two steps: the breaking or detaching of À ÀOH, À ÀCH 2 À À, À ÀCH 3 , OCÀ ÀO and CÀ ÀOÀ ÀC, etc., taking place between 300 and 4508C; and the carbonizing or oxidating of aromatic rings occurring above 4508C. The kinetics of the degradation reaction was studied with Coats-Redfern method showing a first-order process. In addition, vinyl cyclohexene dioxide (VCD) was employed as a reactive diluent for bisANER (VCD/bisANER ¼ 1 : 2 w/w) and cured with MHHPA, and the obtained network had a higher T g and a slight lower degradation temperature than the undiluted system.

Thermal and mechanical behavior of poly(vinyl butyral)‐modified novolac epoxy/multiwalled carbon nanotube nanocomposites

“…The neat novolac epoxy resin showed its first peak degradation temperature ( ) and second peak degradation temperature ( ) at 380 and 405°C, respectively; these were associated with a 3.2 wt % residual yield at 900°C. This good thermal stability of the novolac epoxy resin was attributed to the high crosslinking density of the cured resin . Neat PVB showed a degradation peak at 436°C with a residual yield of 2.1% at 600°C.…”

Tenacious Epoxy Adhesives Prepared from Lignin-derived Stable Metabolic Intermediate

“…The present molar ratio is common to commercial epoxy adhesives (see ref. [18][19]. As for a reference adhesive, DGEBA was used instead of DGPDC.…”

Curing behavior and thermal properties of trifunctional epoxy resin cured by 4, 4’-diaminodiphenyl sulfone

“…One is the maximum reaction rate method proposed by Kissinger, which is based on the fact that the exothermic peak temperature (T p ) varied with the heating rates. The other is the iso-conversion method proposed by Flynn, Wall, and Ozawa, which is based on the fact that iso-conversion can be reached at different temperatures with various heating rates [26]. Kissinger's approach assumed that the maximum reaction rate occurred at peak temperatures, where d 2 α/dt 2 , it can be expressed by Equation (1): (1) where α is the state of cure, β is the linear heating rate [K·min -1 ], T p is he peak temperature [K], A is the pre-exponential factor, E a is the activation energy, and R is the universal gas constant (R = 8.314 kJ/mol·K).…”