Kinetics, thermodynamics and mechanism of reactions of epoxy oligomers with amines

Розенберг, Б. А.

doi:10.1007/bfb0017916

Cited by 369 publications

(158 citation statements)

References 49 publications

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“…In case of the 50% WS sample, a higher intensity of the absorbance peak (at 3500 cm -1 ) may be observed than for unmodified epoxy resin [26,27]. This fact may be attributed both to the presence of the organic filler in the composite material, as well as the effect catalytic reaction of the curing process caused by the presence of additional -OH groups originating from the filler [28,29]. Detailed description of all observed at FT-IR spectra peaks was presented in Table 1.…”

Section: Evaluation Of Composite Materials' Properties and Structurementioning

confidence: 93%

Evaluation of highly filled epoxy composites modified with walnut shell waste filler

et al. 2017

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Epoxy composites modified with ground walnut shell used as organic waste fillers were prepared and examined. Post-agricultural waste materials after grinding were characterized by evaluation of grain size distribution and structure observations realized using scanning electron microscope (SEM). The influence of filler addition on the mechanical properties of epoxy-based composites was determined by: static tensile test, Charpy impact test, and ball indentation hardness measurements. Composite samples containing 20, 30, 40, and 50 wt% of walnut shell were characterized by increased stiffness and hardness in comparison to the unmodified resins. Moreover, the incorporation of the filler resulted in a decrease of composite material tensile strength and impact resistance. Thermo-mechanical properties of the composites were investigated by dynamic mechanical thermal analysis (DMTA). Results obtained from DMTA tests showed a growth in the composites' stiffness at elevated temperatures as a function of the increasing natural filler content. The material characterization was supplemented by thermal stability evaluation realized by thermogravimetric analysis (TGA). It was found that the incorporation of ground walnut shell led to an improved thermal stability of composite materials. The analysis of the change in composite material properties, caused DOI 10.1007DOI 10. /s00289-017-2163 by natural filler incorporation, was complemented by material microstructure observations.

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Section: Evaluation Of Composite Materials' Properties and Structurementioning

confidence: 93%

Evaluation of highly filled epoxy composites modified with walnut shell waste filler

et al. 2017

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“…This remake indicates that the curing reaction is autocatalytic, and within the experiment temperature range, the temperature will little affect the autocatalytic reaction mechanism. As illustrated in Scheme 3, the autocatalytic reaction mechanism results from the hydroxyl groups generated from the epoxy-amine ring-opening reaction that can catalyze the further curing reaction via a trimolecular transition state [34,35]. …”

Section: Figmentioning

confidence: 99%

A sustainable, eugenol-derived epoxy resin with high biobased content, modulus, hardness and low flammability: Synthesis, curing kinetics and structure–property relationship

Wan

Gan

et al. 2016

Chemical Engineering Journal

221

138

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Abstract:To develop functional sustainable epoxy resins, we report a novel epoxy resin (DEU-EP) with high net biobased content (70.2 wt%) derived from renewable eugenol. We comparatively study DEU-EP with a commercial bisphenol A epoxy resin (DGEBA) in the presence of a most representative aromatic diamine curing agent, 4,4'-diaminodiphenyl methane (DDM).Differential scanning calorimetry reveals that DEU-EP can be sufficiently cured by DDM at a slower rate than DGEBA. By applying an autocatalytic reaction model, we adequately simulate the curing rate of DEU-EP/DDM, and reveal its detailed kinetic mechanisms from model-free isoconversional analysis. Dynamic mechanical analysis shows that DEU-EP/DDM takes higher storage modulus up to ~97 o C than DGEBA/DDM with the glass temperature of 114 o C. Nanoindentation and thermogravimetric analysis demonstrate that compared with DGEBA/DDM, DEU-EP/DDM exhibits a 20%, 6.7% and 111% increase in Young's modulus, hardness and char yield, respectively. Microscale combustion calorimetry data show that DEU-EP/DDM expresses 55% and 38% lower heat release rate and total heat release than DGEBA/DDM, respectively.Macroscopically, the horizontal burning test approves DEU-EP/DDM can self-extinguish in a short time. Our results demonstrate that the eugenol building blocks and their arrangement greatly affect the cure behaviors of DEU-EP/DDM, and contribute significantly to its enhanced mechanical properties, high-temperature charring ability and chain motions at glass state, as well as the reduced flammability. To summarize, DEU-EP exhibits a high promise as a new sustainable epoxy monomer for fabricating high biobased content, high rigid and low flammable epoxy materials.

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“…The addition of CNTs [19,20,31] and EG [24] decreased the "H of epoxy, whereas CNF had no pronounced effect on the heat of the TGDDM/DDS cure reaction [32] and silanized and polyaniline modified CNFs increased the "H of epoxy [33,34]. It is believed that the addition of hydroxyl-containing compounds (water, alcohols, phenols, acids) considerably promoted the interaction of epoxy compounds with amines and other nucleophilic reagents [35]. In this case, the epoxy ring carbon atom became more sensitive to nucleophilic attack.…”

Section: Effects Of Gos On the Cure Reactionmentioning

confidence: 99%

Effects of graphene oxides on the cure behaviors of a tetrafunctional epoxy resin

Qiu¹,

Wang²,

Wang³

et al. 2011

Express Polym. Lett.

135

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The influence of graphene oxides (GOs) on the cure behavior and thermal stability of a tetrafunctional tetraglycidyl-4,4’-diaminodiphenylmethane cured with 4,4’-diaminodiphenylsulfone was investigated by using dynamic differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic DSC results showed that the initial reaction temperature and exothermal peak temperature decreased with the increase of GO contents. Furthermore, the addition of GO increased the enthalpy of epoxy cure reaction. Results from activation energy method showed that activation energies of GO/epoxy nanocomposites greatly decreased with the GO content in the latter stage, indicating that GOs significantly hindered the occurrence of vitrification. The oxygen functionalities, such as hydroxyl and carboxyl groups, on the surface of GOs acted as catalysts and facilitated the curing reaction and the catalytic effect increased with the GO contents. TGA results revealed that the addition of GOs decreased the thermal stability of epoxy

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Kinetics, thermodynamics and mechanism of reactions of epoxy oligomers with amines

Cited by 369 publications

References 49 publications

Evaluation of highly filled epoxy composites modified with walnut shell waste filler

Evaluation of highly filled epoxy composites modified with walnut shell waste filler

A sustainable, eugenol-derived epoxy resin with high biobased content, modulus, hardness and low flammability: Synthesis, curing kinetics and structure–property relationship

Effects of graphene oxides on the cure behaviors of a tetrafunctional epoxy resin

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