Non-isothermal cure and decomposition kinetics of epoxy–imidazole systems

Leena, K.; Soumyamol, Panthaplackal Bhaskaran; Baby, Monisha; Suraj, S.; Ramanan, Rajeev; Mohan, Dhanya S.

doi:10.1007/s10973-017-6410-5

Cited by 27 publications

(12 citation statements)

References 15 publications

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“…8, 9). For the first exothermic peak, the activation energy remained constant for the entire range of conversion; similar results were also observed by Leena et al 42 . For the second exothermic peak, the activation energy increased along with the percentage conversation.…”

Section: Resultssupporting

confidence: 89%

“…Thus, the curing mechanism of GSPZ-EP may be similar to that of imidazoles, as they not only show similar curing activation energy 41 , but also contain similar tertiary amines. In addition, most epoxy resins cured with imidazoles also display two curing exothermic peaks 42–44 . In agreement with the previous literature 45,46 , we propose the mechanism for self-curing GSPZ-EP as depicted in Fig.…”

Section: Resultsmentioning

confidence: 99%

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Synthesis of an aromatic N-heterocycle derived from biomass and its use as a polymer feedstock

et al. 2019

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Aromatic N-heterocyclic compounds are very important chemicals, which are currently produced mostly from petroleum. Here we report that a pyridazine-based compound 6-(4-hydroxy-3-methoxyphenyl)pyridazin-3(2H)-one (GSPZ) can be efficiently synthesized by the Friedel-Crafts reaction of guaiacol and succinic anhydride, both of which can be derived from biomass. GSPZ is then treated with bio-based epichlorohydrin to prepare the epoxy resin precursor GSPZ-EP. With 4,4'-diaminodiphenylmethane as curing agent, GSPZ-EP possesses higher glass transition temperature (187 o C vs. 173 o C) and shows a 140%, 70 and 93% increase in char yield (in N 2 ), storage modulus (30 o C) and Young’s modulus, respectively when compared with a standard petroleum-based bisphenol A epoxy resin. Moreover, the cured GSPZ-EP shows good intrinsic flame retardancy properties and is very close to the V-0 rating of UL-94 test. This work opens the door for production of aromatic N-heterocyclic compounds, which can be derived from biomass and employed to construct high performance polymers.

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Synthesis of an aromatic N-heterocycle derived from biomass and its use as a polymer feedstock

et al. 2019

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“…Curing of an epoxy-amine mixture proceeds through different reaction mechanisms. In competition with the main stepwise polycondensation reaction between epoxy and amine groups [18], homopolymerization of epoxy groups can take place at higher temperatures and can be catalyzed by the tertiary amines formed by the polycondensation reaction or additional anionic initiators [20,21].…”

Section: Epoxy Network Isothermal Cure Thermal Cure Kineticsmentioning

confidence: 99%

Curing of off-stoichiometric amine–epoxy thermosets

Morancho¹,

Ramis²,

Fernández‐Francos³

et al. 2018

J Therm Anal Calorim

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The kinetics of the epoxy-amine polycondensation and the epoxy homopolymerization in off-stoichiometric epoxy/amine formulations with excess of epoxy groups, and in the presence of an anionic initiator have been investigated. Diglycidyl ether of bisphenol A (DGEBA) and diethylenetriamine (DETA) have been used as epoxy and amine reagents, respectively, and 2-methylimidazole (2MI) has been used as anionic initiator. This study has been carried out using a differential scanning calorimeter (DSC). The thermal-mechanical properties of the partially cured and fully cured materials with and without initiator have been determined by DSC and dynamic-mechanical analysis.

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“…Based on Eqs 1 and 2, through a linear fit between lnβ/T 2 p and 1/T p (Hardis et al, 2013;Ferdosian et al, 2015), the value of activation energy E a can be obtained from the slope of the fitted line. The E a of the EGE-2-MI resin can be calculated as 86.34 kJ/mol, while the apparent activation energy of unmodified 2-MI was 50.34 kJ/mol by preliminary experiment (Leena et al, 2017). Activation energy is a measure of the energy required for a curing reaction: the higher the value, the more the energy needed.…”

Section: Curing Kinetics Analysismentioning

confidence: 99%

“…Among all kinds of curing agents that can be used in epoxy resin systems, a conjugated molecule, imidazole and its derivatives have some distinguishing properties (Ham et al, 2010;Leena et al, 2017). They have extremely high reactivity in chain polymerization with epoxy resin, superior heat resistance, low tensile elongation, and outstanding adaptability for molecular design, which opens up the possibility of altering the nucleophilic and base-catalyzed processes during polymerization (Unruh et al, 2011;Arimitsu et al, 2015;Zhao et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of a Modified Conjugated Molecule-Based Moderate-Temperature Curing Epoxy Resin System

et al. 2020

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A 2-Methylimidazole derivative [ethyl glycidyl ether (EGE)-2-MI] was synthesized through the reaction of EGE with the conjugated molecule 2-MI. The structure was confirmed by Fourier transform infrared spectroscopy, 1 H-nuclear magnetic resonance spectroscopy, and differential scanning calorimeter. The synthesized EGE-2-MI was applied in epoxy resin E-51 as a latent curing agent. Kinetics of the curing reaction were studied by a differential scanning calorimeter method, optimum curing process parameters were determined, storage life of the resin system at room temperature was evaluated, and mechanical properties of the moderate-temperature-cured products were also tested and analyzed. The results revealed that the epoxy resin system using EGE-2-MI as the curing agent can be efficiently cured at 110-120°C, with an activation energy of 86.34 kJ/mol. The storage period of the EGE-2-MI/cyanate resin system can reach 14 days under ambient temperature. In addition, the cured mixture with EGE-2-MI/cyanate resin has a tensile strength of 40 MPa and an Al-Al adhesion shear strength of 20.11 MPa.

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Non-isothermal cure and decomposition kinetics of epoxy–imidazole systems

Cited by 27 publications

References 15 publications

Synthesis of an aromatic N-heterocycle derived from biomass and its use as a polymer feedstock

Synthesis of an aromatic N-heterocycle derived from biomass and its use as a polymer feedstock

Curing of off-stoichiometric amine–epoxy thermosets

Fabrication and Characterization of a Modified Conjugated Molecule-Based Moderate-Temperature Curing Epoxy Resin System

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