A novolac epoxy resin based on 4,4 0 -dihydroxybenzophenone (BZPNE) was synthesized via epoxidation of 4,4 0 -dihydroxybenzophenone novolac resin (BZPN). BZPN was obtained by strong mineral acid catalyzed reaction of 4,4 0 -dihydroxybenzophenone (BZP) and paraformaldehyde. The formation of BZPNE and BZPN was confirmed by Fourier transform infrared spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy, gel permeation chromatography, and epoxy equivalent weight. Different blends of BZPNE with diglycidyl ether of bisphenol-A (DGEBA; EEW $180) were cured using dicyandiamide were characterized by thermogravimetric analysis, thermomechanical analysis, dynamic mechanical analysis, and interfacial property between aluminum adherends at ambient and elevated temperature. Thermal properties were found to improve on increasing quantity of BZPNE in DGEBA as it is evidenced from glass transition temperature (T g ). Likewise, no deterioration in interfacial properties was observed with the highest quantity of BZPNE (30%) in DGEBA blend, when tested at 150 8C. Cure kinetics of compositions were studied by nonisothermal differential scanning calorimetry and Kissinger method was used to compute the kinetic parameters such as frequency factor (A), activation energy (E a ) followed by the dependency of rate constant (k) on temperature of different blends. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46164.

Epoxy film adhesives are of prime importance for the fabrication of lightweight honeycomb structures for aerospace industries. This work involves the synthesis of oxazolidinone modified epoxy novolac resin (EPN‐OXA) via the reaction of EPN and toluene diisocyanate. EPN‐OXA was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, and epoxy equivalent weight. EPN‐OXA was blended with solid epoxy resin, polyethersulfone (PES) toughened liquid epoxy resin, dicyandiamide, and aluminum powder to fabricate a film adhesive curing at 170–180 °C. Effect of additives and curative on the adhesive property was studied to optimize the composition. Effect of PES on the optimized composition was studied in detail. The best composition exhibited lap shear strength of 370 ± 10 kgf cm−2 at 25 °C and the strength was retained to 75% at −196 °C and 52% at 120 °C. PES significantly enhanced the interfacial strength at different temperatures (~1.6‐fold at −196 and 25 °C and ~1.8‐fold at 120 °C). It also improved tensile strength and fracture toughness by 1.4‐ and 2‐fold, respectively. The toughening effect of PES was further confirmed by scanning electron microscopy images. PES marginally reduced the glass‐transition temperature and it exhibited no effect on thermal stability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47520.

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