A perspective approach on the amine reactivity and the hydrogen bonds effect on epoxy-amine systems

Mora, A.; Tayouo, Russell; Boutevin, Bernard; David, Ghislain; Caillol, Sylvain

doi:10.1016/j.eurpolymj.2019.109460

Cited by 63 publications

(61 citation statements)

References 121 publications

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“…The stoichiometric amount of curing agents (CAs) was easily calculated from the epoxide equivalent weight (EEW) and amine hydrogen equivalent weight (AHEW), according to Equations (1) and (2) 24 :

CA ((), phr) = ((), AHEW / EEW) \times 100,

where:

AHEW = ((), Molecular weight of amine) / ((), Number of active hydrogens) .

…”

Section: Methodsmentioning

confidence: 99%

Investigation of the cure kinetics and thermal stability of an epoxy system containing cystamine as curing agent

Khalafi

Ehsani

Khonakdar

2020

Polymers for Advanced Techs

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2,2′‐Dithiobisethanamine (cystamine), an aliphatic diamine containing exchangeable disulfide bonds, was used as the curing agent for epoxy resin. The dynamic curing kinetics and thermal stability of the epoxy/cystamine system were investigated by DSC and TGA analysis. Applied the Málek method, the Sestak–Berggren autocatalytic equation was selected to describe the cure kinetics of the epoxy/cystamine system. The results showed that the Šesták– Berggren equation is in good agreement with the experimental data. The activation energy of the curing reaction was 56.2 and 53.6 kJ mol −1, respectively, calculated by Kissinger and KAS models. Also, the glass transition temperature for the epoxy/cystamine system was slightly than that of the commonly used epoxy‐diamine systems. Moreover, the thermal degradation of the cured epoxy/cystamine network was observed at temperatures above 283°C. Further, the results obtained from the epoxy/cystamine system were compared with those obtained from the epoxy/diethylenetriamine system. All the above results suggest that cystamine has the potential to be used as the curing agent for epoxy systems.

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CA ((), phr) = ((), AHEW / EEW) \times 100,

where:

AHEW = ((), Molecular weight of amine) / ((), Number of active hydrogens) .

…”

Section: Methodsmentioning

confidence: 99%

Investigation of the cure kinetics and thermal stability of an epoxy system containing cystamine as curing agent

Khalafi

Ehsani

Khonakdar

2020

Polymers for Advanced Techs

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“…In general, there are two factors infl uencing a chemical reaction such as the frequency factor and the activation energy. The molecular design for epoxy resins has been extensively studied from the viewpoint of the activation energy [13][14][15][16] . The activation energy of the reaction between epoxy and amino groups may change depending on the difference of adjacent functional group/s.…”

Section: Introductionmentioning

confidence: 99%

“…The activation energy of the reaction between epoxy and amino groups may change depending on the difference of adjacent functional group/s. In addition, an OH group in the reaction space accelerates the ring opening reaction of the epoxy group by hydrogen bond as a catalyst and also affects the reaction of the amino group 13,15) . On the other hand, it seems to us that there is a lack of study dealing with the molecular design based on the frequency factors, namely the molecular mobility and the steric hindrance of reactants.…”

Section: Introductionmentioning

confidence: 99%

Molecular Size Effect on Curing Process for Epoxy and Amine Mixture

Yamamoto

Tanaka

2021

J. Soc. Rheol., Jpn

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The curing process of epoxy and amine mixtures was investigated from the viewpoint of molecular size of reactants via all-atom molecular dynamics simulation. Of four mixtures composed of either smaller or larger epoxy and amine molecules, the system of both smaller epoxy and amine reached the highest conversion at a given time, whereas the conversion for the combination of both larger epoxy and amine was the lowest. These can be explained in terms of their diffusion coeffi cients. In addition, the size effect on the reaction kinetics was more striking for epoxy than amine in the curing process. This was because epoxy reacted only once but amine did twice. When the primary amine reacted with epoxy, the resultant secondary amine was incorporated into the three-dimensional network. Hence, even if the primary amine had a higher mobility, the movement of the part after the reaction slowed down, making the further reaction to be the tertiary amine slow. Finally, it was shown that although the smaller epoxy reacted faster than the larger one in the mixed system of larger/smaller epoxy and amine, there was no difference in the reaction progress depending on the molecular size of amine.

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“…In the 40% NMDG solution, the chelating capacity reaches 1.74 mmol/g, which corresponds to 58.4% conversion of the epoxy rings to NMDG moieties. Because of steric hindrance and side reactions, a large number of epoxy rings are not converted to the NMDG moieties [ 38 ]. Prolonging the reaction time to 24 h or increasing the reaction temperature to 100 °C had almost no effect on the further increase in conversion.…”

Section: Resultsmentioning

confidence: 99%

Chelating Fabrics Prepared by an Organic Solvent-Free Process for Boron Removal from Water

et al. 2021

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A chelating fabric was prepared by graft polymerization of glycidyl methacrylate (GMA) onto a nonwoven fabric, followed by attachment reaction of N-methyl-D-glucamine (NMDG) using an organic solvent-free process. The graft polymerization was performed by immersing the gamma-ray pre-irradiated fabric into the GMA emulsion, while the attachment reaction was carried out by immersing the grafted fabric in the NMDG aqueous solution. The chelating capacity of the chelating fabric prepared by reaction in the NMDG aqueous solution without any additives reached 1.74 mmol/g, which further increased to above 2.0 mmol/g when surfactant and acid catalyst were added in the solution. The boron chelation of the chelating fabric was evaluated in a batch mode. Fourier transform infrared spectrophotometer (FTIR) was used to characterize the fabrics. The chelating fabric can quickly chelate boron from water to form a boron ester, and a high boron chelating ability close to 18.3 mg/g was achieved in the concentrated boron solution. The chelated boron can be eluted completely by HCl solution. The regeneration and stability of the chelating fabric were tested by 10 cycles of the chelation-elution operations. Considering the organic solvent-free preparation process and the high boron chelating performance, the chelating fabric is promising for the boron removal from water.

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A perspective approach on the amine reactivity and the hydrogen bonds effect on epoxy-amine systems

Cited by 63 publications

References 121 publications

Investigation of the cure kinetics and thermal stability of an epoxy system containing cystamine as curing agent

Investigation of the cure kinetics and thermal stability of an epoxy system containing cystamine as curing agent

Molecular Size Effect on Curing Process for Epoxy and Amine Mixture

Chelating Fabrics Prepared by an Organic Solvent-Free Process for Boron Removal from Water

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