Novel macromolecular epoxy resin curing agent containing biphenyl and maleimide moieties: Preparation, curing kinetics, and thermal properties of its cured polymer

Abstract

A new curing agent containing maleimide and biphenyl moieties (MIBP) was synthesized by the condensation polymerization of 4,4′‐bismethoxymethylbiphenyl and N‐(4‐hydroxyphenyl)maleimide (HPM). The chemical structure was characterized with Fourier transform infrared (FTIR) spectroscopy, and the molecular weight of the new curing agent was determined by gel permeation chromatography. Curing reactions of O‐cresol formaldehyde epoxy (CNE) resin with MIBP were investigated under nonisothermal differential scanning calorimetry, and the exotherm exhibited two overlapping exothermic peaks during the curing process; this was demonstrated by FTIR traces. The Flynn–Wall–Ozawa and Friedman methods were used to examine the kinetic parameters and the kinetic models of the curing processes of the CNE/MIBP mixtures. Both reactions turned out to be nth‐order curing mechanisms. Values of the reaction order (n) = 1.42 and activation energy (Ea) = 91.2 kJ/mol were obtained for the first reaction of the curing of the CNE/MIBP system, and values of n = 1.11 and Ea = 78.7 kJ/mol were obtained for the second reaction. The thermal properties of the cured resin were measured with thermogravimetric analysis, and the results show a high glass‐transition temperature (Tg = 155°C), good thermal stability (temperature at 10% weight loss, under nitrogen and in air, ≈ 400 and 408°C, respectively), and high char yield (temperature = 800°C, char residue = 44.5% under nitrogen). These excellent thermal properties were due to the introduction of the maleimide and biphenyl groups of MIBP into the polymer structure. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis and thermal stability properties of boron‐doped silicone resin

“…These IR absorption variations indicate that, the BSR degradation begins with the breaking small groups as CH 3 and C 3 H 7 from the side chains. This process is confirmed by the increased absorption bands at 2966 cm −1 , 2880 cm −1 , 1270 cm −1 , 1220 cm −1 , and1115 cm −1 in Figure (curve c, when the sample heated for 40 min and temperature up to 430°C), which may be assigned to the stretching vibration of v CH, and the stretching vibration of v CO or v CC, respectively . With the increase of temperature, the intensity of these absorption bands increased gradually.…”

Effect of the addition of multi-walled carbon nanotubes on the thermomechanical properties of epoxy resin

“…The decrease in stability with addition of MWCNTs is surprising since the MWCNTs have a decomposition temperature which is ∼150–250°C higher than that of epoxy resin . However, the thermal stability and decomposition temperatures of epoxy are reported to be strongly dependent on the degree of cure and the resulting crosslink density and it is considered, therefore, that the decrease in thermal stability in the present study is the result of the MWCNTs obstructing crosslinking during the cure process. The reduced level of crosslinking would also account for the reduction in T g observed in the DMA testing.…”

Effect of Surface Modification on Mechanical Properties of Quartz Fiber Reinforced Boron Doped Silicone Resin Composites

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