Activation energies and rate constants for an epoxy/cure agent reaction

Núñez, Lisardo; Fraga, F.; Grueiro, L. Fraga; Añón, Jose Antonio Rodríguez

doi:10.1007/bf01981809

Cited by 25 publications

(4 citation statements)

References 8 publications

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“…For small initial temperatures, it is reasonable to assume that α 0 = 0 and admitting that there is no reaction between 0 and T 0 [53], the integral conversion function, g (α), can be defined in this way:…”

Section: Kinetic Methodsmentioning

confidence: 99%

Extraction and Physicochemical Characterization of Chitin Derived from the Asian Hornet, Vespa velutina Lepeletier 1836 (Hym.: Vespidae)

et al. 2020

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Fifteen years ago, at least one multimated female yellow-legged Asian hornet (Vespa velutina Lepeletier 1836) arrived in France, which gave rise to a pan-European invasion. In this study, the isolation and characterization of chitin (CHI) that was obtained from Vespa velutina (CHIVV) is described. In addition, an easy procedure is carried out to capture the raw insect, selectively and with high rates of success. The chitin contents of dry VV was observed to be 11.7%. Fourier transform infrared spectroscopy (FTIR), solid-state NMR (ssNMR), elemental analysis (EA), scanning electron microscopy (SEM), and thermogravimetric analysis (TG) characterized the physicochemical properties of CHIVV. The obtained CHIVV is close to pure (43.47% C, 6.94% H, and 6.85% N), and full acetylated with a value of 95.44%. Additionally, lifetime and kinetic parameters such as activation E and the frequency factor A using model-free and model-fitting methods, were determined. For CHIVV the solid state mechanism that follows the thermodegradation is of type F2 (random nucleation around two nuclei). The invasive Asian hornet is a promising alternative source of CHI, based on certain factors, such as the current and probable continued abundance of the quantity and quality of the product obtained.

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Section: Kinetic Methodsmentioning

confidence: 99%

Extraction and Physicochemical Characterization of Chitin Derived from the Asian Hornet, Vespa velutina Lepeletier 1836 (Hym.: Vespidae)

et al. 2020

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“…An assumption is made that the reaction probability corresponds to the reaction rate. According to ref , the activation energy of the epoxy resin cross-linking reaction is around E a = 57.48 J/mol. The reaction probability is derived from the activation energy as italicP normalr ( t ) = A .1em exp [ − E a / false( italicN normalA italick normalB italicT false) ] [ M ] ( t ) false[ M 0 false] , where A is a dimensionless factor with the value of 2.2 × 10 5 and N A is Avogadro number.…”

Section: Methodsmentioning

confidence: 99%

Automatic Multiscale Method of Building up a Cross-linked Polymer Reaction System: Bridging SMILES to the Multiscale Molecular Dynamics Simulation

Pei

Zhu

et al. 2023

J. Phys. Chem. B

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An automatic method is introduced to generate the initial configuration and input file from SMILES for multiscale molecular dynamics (MD) simulation of cross-linked polymer reaction systems. Inputs are a modified version of SMILES of all the components and conditions of coarse-grained (CG) and allatom (AA) simulations. The overall process comprises the following steps: (1) Modified SMILES inputs of all the components are converted to 3-dimensional coordinates of molecular structures. (2) Molecular structures are mapped to the coarse-grained scale, followed by a CG reaction simulation. (3) CG beads are backmapped to the atomic scale after the CG reaction. (4) An AA productive run is finally performed to analyze volume shrinkage, glass transition, and atomic detail of network structure. The method is applied to two common epoxy resin reactions, that is, the cross-linking process of DGEVA (diglycidyl ether of vanillyl alcohol) and DHAVA (dihydroxyaminopropane of vanillyl alcohol) and that of DGEBA (diglycidyl ether of bisphenol A) and DETA (diethylenetriamine). These components form network structures after the CG cross-linking reaction and are then backmapped to calculate properties in the atomic scale. The result demonstrates that the method can accurately predict volume shrinkage, glass transition, and all-atom structure of cross-linked polymers. The method bridges from SMILES to MD simulation trajectories in an automatic way, which shortens the time of building up cross-linked polymer reaction model and suitable for highthroughput computations.

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“…5). One peak was first observed which was attributed to the reaction of epoxy group with the aliphatic group -CH2NH2 and a shoulder attributed to the alicyclic group [49].…”

Section: Non-isothermal Scanning Methodsmentioning

confidence: 99%

Development of new graphene/epoxy nanocomposites and study of cure kinetics, thermal and mechanical properties

et al. 2020

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New graphene/polymer nanocomposites were prepared using graphene nanoplatelets (GNPs) and the epoxy system Epilok 60-566/Curamine 32-494. The GNPs were first dispersed into the curamine hardener using bath ultrasonication, followed by the addition of the epoxy resin. The cure kinetics were studied by DSC under non-isothermal and under isothermal conditions. The kinetic parameters of the curing process were determined using the non-isothermal Kissinger and Ozawa-Flynn-Wall models. The degree of curing increased with the addition of GNPs, while the activation energy decreased by 13.7% for the first reaction and by 6.6% for the second as obtained from Kissinger. An increase in thermal stability by the addition of GNPs was identified in the range of 360-580℃ using TGA. In terms of mechanical properties, addition of an optimum amount of 0.5%wt of GNPs in the hardener improved the Young's Modulus by 37%. Nanoindentation measurements showed 9.4% improvement in hardness at 0.7%wt.

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Activation energies and rate constants for an epoxy/cure agent reaction

Cited by 25 publications

References 8 publications

Extraction and Physicochemical Characterization of Chitin Derived from the Asian Hornet, Vespa velutina Lepeletier 1836 (Hym.: Vespidae)

Extraction and Physicochemical Characterization of Chitin Derived from the Asian Hornet, Vespa velutina Lepeletier 1836 (Hym.: Vespidae)

Automatic Multiscale Method of Building up a Cross-linked Polymer Reaction System: Bridging SMILES to the Multiscale Molecular Dynamics Simulation

Development of new graphene/epoxy nanocomposites and study of cure kinetics, thermal and mechanical properties

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