Effect of polyethersulfone and N,N’-bismaleimido-4,4’-diphenyl methane on the mechanical and thermal properties of epoxy systems

Abstract

Abstract. In order to improve thermo mechanical properties of cured epoxy resin, hydroxyl terminated polyethersulfone (PES) and N,N′-bismaleimido-4,4′-diphenyl methane (BMI) were incorporated to diglycidyl ether of bisphenol A (DGEBA) type epoxy resin and cured with diaminiodiphenylmethane (DDM). The resulting hybrid matrices, in the form of castings, were characterized for their mechanical properties like tensile, flexural and impact strength. Differential scanning calorimetry, dynamic mechanical analysis and thermogravimetric analysis of the matrices were also performed to determine the glass transition temperature and thermal stability of the matrix systems. The results obtained from mechanical and thermal studies indicated that the incorporation of polyethersulfone into epoxy resin improved the toughness and thermal stability of the systems. This is attributed to the formation of interpenetration polymer networks (IPNs) composed of the epoxy network and the linear PES. The incorporation of BMI into polyethersulfone modified epoxy systems increased thermal stability, glass transition temperature, tensile and flexural properties and decreased the impact strength. Scanning electron microscopy studies of polyethersulfone modified epoxy and BMI incorporated polyethersulfone modified epoxy systems exhibit homogeneous morphology confirming efficient chemical interaction and formation of intercrosslinked network structure.Keywords : polymer composites, thermal properties, mechanical properties, morphology, moisture absorption eXPRESS Polymer Letters Vol.2, No.5 (2008) [339][340][341][342][343][344][345][346][347][348] Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2008.40 homogeneous hybrid thermoplastic modified epoxy with low fractions of thermoplastics [18]. It is reported that the incorporation of high performance thermoplastics into a thermoset resin system leads to significant improvements in mechanical properties [9,[19][20][21][22] [28][29][30][31][32]. Bismaleimides posses high crosslinking ability, high glass-transition temperature, high thermal ability, high char yield, excellent fire resistance, superior specific strength and specific modulus, and low water absorption. In continuation of our earlier studies, an attempt has been made in the present investigation to improve both toughness and thermo-mechanical properties of epoxy resin by incorporating hydroxyl terminated polyethersulfone (PES) and N,N′-bismaleimido-4,4′-diphenyl methane(BMI). Materials and methodsEpoxy resin [diglycidyl ether of bisphenol A (DGEBA)] LY556 (epoxy equivalent 189 and viscosity 10 000 cP) and 4,4′-diaminodiphenylmethane (DDM) were obtained from Ciba-Geigy (India). N,N′-bismaleimido-4,4′-diphenyl methane was synthesized in our laboratory as per the reported procedure ( Figure 1) [33]. Hydroxyl terminated polyethersulfone was supplied by Jilin University, China was used as received. The chemical structures of materials used are presented in Figure 2.340 Rajasekaran et al. -eXPRESS Polymer Let...

Preparation and properties of mesoporous silica/bismaleimide/diallylbisphenol composites with improved thermal stability, mechanical and dielectric properties

“…Dielectric property was conducted over a frequency range from 10 to 10 6 Hz at room temperature using a Broad Band Dielectric Spectrometer (Novocontrol Concept 80 Analyzer, Germany). The dimensions of each sample were (25±0.2)#(25±0.2)# (3±0.1) mm 3 . The powders of MPSA were pressed into a pellet with a diameter of 20 mm and a thickness of 3 mm.…”

Specific influence of polyethersulfone functionalization on the delamination toughness of modified carbon fiber reinforced polymer processed by resin transfer molding

“…Similarly, hydroxyl‐terminated PSF was a better toughener for a Diglycidyl Ether of Bisphenol A (DGEBA) epoxy resin than chlorine‐terminated PSF. Rajasekaran et al incorporated a PES‐OH/bismaleimide hybrid with TMAH catalyst in an epoxy network based on DGEBA cured with diaminodiphenyl methane (DDM) and found a 68% improvement of G Ic upon addition of 12 wt% PES‐OH. On the contrary, Yoon et al observed a detrimental influence of reactive amino‐terminated PES compared to that of a nonreactive PSF on the toughening of a DGEBA/DDS system.…”

Study on Characteristics of Various RF Transmission Line Structures on PES Substrate for Application to Flexible MMIC

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“…Recently, PES (poly[ether sulfone]) has drawn attention for its application to transparent flexible displays due to its notable heat-resisting property, high transparency, and flexibility [5]- [8]. Concretely, the glass transition temperature (T g ) of PES is 230°C, and it shows stable electrical and mechanical properties at high temperatures, which enables the fabrication of electron devices at a relatively high temperature [5]- [8]. For a heatresisting property with a short duration, electrical and mechanical properties of PES do not change, even at 300°C.…”