Study of the Cure of a Diglycidyl-Ether of Bisphenol-a (DGEBA) / Triethylenetetramine (TETA) Epoxy System by Non-Isothermal Differential Scanning Calorimetry (DSC)

2006 ◽  
Vol 514-516 ◽  
pp. 1094-1098
Author(s):  
Rosa Losada ◽  
José Luís Mier ◽  
Fernando Barbadillo ◽  
Ramón Artiaga ◽  
Angel Varela ◽  
...  
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Bisphenol A ◽  
Inert Atmosphere ◽  
Diglycidyl Ether ◽  
Exothermic Peak ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Reaction Heat ◽  
Marine Coatings

A diglycidyl-ether of bisphenol-A (DGEBA)/Triethylenetetramine (TETA) system was studied by non-isothermal differential scanning calorimetry (DSC) to establish its kinetics of cure. The DGEBA resin was Araldite GZ 601 X75 used in the marine coatings formulations. Previously, the optimum resin/hardener ratio was determined by the reaction heat measuring (.Hc) calculated from the curing exothermic peak. Tests at different heating rates (10, 15, 20, 25 and 30°C/min) under inert atmosphere were carried out in order to study the reaction kinetics. The activation energy of the cure (Ea) was obtained from these tests data by Borchardt-Daniels, autocatalytic, Duswalt and isoconversional Ozawa methods. Once the activation energy was determined, the master curves method was applied to find the kinetic model which best describes the measured DSC data. The Sestak-Berggren model SB (m,n) was found to be the most adequate for the system studied.

scholarly journals Kinetic Analysis of the Curing of a Partially Biobased Epoxy Resin Using Dynamic Differential Scanning Calorimetry

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 391 ◽  
Author(s):  
Diego Lascano ◽  
Luis Quiles-Carrillo ◽  
Rafael Balart ◽  
Teodomiro Boronat ◽  
Nestor Montanes
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Reaction Model ◽  
Diglycidyl Ether ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Model Free

This research presents a cure kinetics study of an epoxy system consisting of a partially bio-sourced resin based on diglycidyl ether of bisphenol A (DGEBA) with amine hardener and a biobased reactive diluent from plants representing 31 wt %. The kinetic study has been carried out using differential scanning calorimetry (DSC) under non-isothermal conditions at different heating rates. Integral and derivative isoconversional methods or model free kinetics (MFK) have been applied to the experimental data in order to evaluate the apparent activation energy, Ea, followed by the application of the appropriate reaction model. The bio-sourced system showed activation energy that is independent of the extent of conversion, with Ea values between 57 and 62 kJ·mol−1, corresponding to typical activation energies of conventional epoxy resins. The reaction model was studied by comparing the calculated y(α) and z(α) functions with standard master plot curves. A two-parameter autocatalytic kinetic model of Šesták–Berggren [SB(m,n)] was assessed as the most suitable reaction model to describe the curing kinetics of the epoxy resins studied since it showed an excellent agreement with the experimental data.

Glass transformation temperature and stability of tellurite glasses

2003 ◽  
Vol 18 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Raouf El-Mallawany
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Transformation Temperature ◽  
Unit Volume ◽  
Tellurite Glasses ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Glass Transformation ◽  
Glass Series ◽  
Calculated Number

The glass transformation (Tg) and onset crystallization temperatures (Tx) of (100 – x) TeO2–(x)V2O5, (x = 10, 35, and 50 mol%) glasses were measured in the temperature range 300–800 K by differential scanning calorimetry at different heating rates. From the variation of the heating rate, the glass transition activation energy was calculated by different methods. The glass stabilization range S = Tx – Tg was calculated for the whole glass series. Quantitative analysis of the glass transformation temperature was carried out using the calculated number of bonds per unit volume and oxygen packing density.

scholarly journals Novel Bio-Based Epoxy Thermosets Based on Triglycidyl Phloroglucinol Prepared by Thiol-Epoxy Reaction

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 337 ◽  
Author(s):  
Dailyn Guzmán ◽  
David Santiago ◽  
Àngels Serra ◽  
Francesc Ferrando
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Bisphenol A ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
High Transparency ◽  
Epoxy Curing ◽  
Curing Agents

The pure trifunctional glycidyl monomer from phloroglucinol (3EPO-Ph) was synthesized and used as feedstock in the preparation of novel bio-based thermosets by thiol-epoxy curing. The monomer was crosslinked with different commercially available thiols: tetrafunctional thiol (PETMP), trifunctional thiol (TTMP) and an aromatic dithiol (TBBT) as curing agents in the presence of a base. As catalyst, two different commercial catalysts: LC-80 and 4-(N,N-dimethylamino) pyridine (DMAP) and a synthetic catalyst, imidazolium tetraphenylborate (base generator, BG) were employed. The curing of the reactive mixtures was studied by using DSC and the obtained materials by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results revealed that only the formulations catalyzed by BG showed a latent character. Already prepared thermosetting materials showed excellent thermal, thermomechanical and mechanical properties, with a high transparency. In addition to that, when compared with the diglycidyl ether of bisphenol A (DGEBA)/PETMP material, the thermosets prepared from the triglycidyl derivative of phloroglucinol have better final characteristics and therefore this derivative can be considered as a partial or total renewable substitute of DGEBA in technological applications.

Study on Thermal Degradation Characteristics of Pre-Treated Paraffin

2014 ◽  
Vol 496-500 ◽  
pp. 246-250
Author(s):  
Song Qi Hu ◽  
Guan Jie Wu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Degradation ◽  
Heat Release ◽  
Kinetic Parameters ◽  
Decomposition Temperature ◽  
Exothermic Peak ◽  
Initial Reaction ◽  
Scanning Calorimetry ◽  
Reaction Heat ◽  
Different Temperatures

The paraffin, pre-treated paraffin and hydroxyl-terminated polybutadiene (HTPB) were measured by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) in different conditions. Thermal degradation characteristics of the paraffin, pre-treated paraffin and HTPB were studied; Influences of different pressure and different temperatures on thermal degradation characteristics of pre-treated paraffin were analyzed. Experiments show that the decomposition temperature of pre-treated paraffin is higher than that of the untreated paraffin, but lower than that of HTPB; the initial reaction temperature, the reaction exothermic peak temperature and the reaction heat release of pre-treated paraffin were all affected by pressure and heating rate; Kinetic parameters of pre-treated paraffin in oxygen atmosphere were calculated.

Estimation of Cure and Thermal Degradation Kinetics of Epoxy/Organoclay Nanocomposite

2010 ◽  
Vol 123-125 ◽  
pp. 667-670 ◽  
Author(s):  
Jae Young Lee ◽  
Bum Choul Choi ◽  
Hong Ki Lee
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Epoxy Matrix ◽  
Degradation Kinetics ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Kinetics Of

Polymer nanocomposite was synthesized through the intercalation and exfoliation of organoclay in an epoxy matrix. The epoxy matrix was composed of diglycidyl ether of bisphenol A (DGEBA, epoxy base resin), 4,4'-methylene dianiline (MDA, curing agent) and malononitrile (MN, chain extender) and organoclay was prepared by treating the montmorillonite with octadecyltrimethylammonium bromide (ODTMA). The intercalation of the organoclay was estimated by wide angle X-ray diffraction (WAXD) and transmission electron microscope (TEM) analyses. In order to measure the cure rate of DGEBA/MDA (30 phr)/MN (5 phr)/Organoclay (5 phr), differential scanning calorimetry (DSC) analysis were performed at the heating rates of 5, 10, 15 and 20 oC/min, and the data was interpreted by Kissinger equation. Thermal degradation kinetics of the epoxy nanocomposite was also studied by thermogravimetric analysis (TGA). The epoxy sample was decomposed in the TGA furnace at the heating rates of 5, 10, 15 and 20 oC/min with nitrogen atmosphere of 50 ml/min. The TGA data was introduced to the Ozawa equation and the degradation activation energy was calculated according to the degradation ratio. The activation energy for cure kinetics was 43.3 kJ/mol and that for thermal degradation was 171.5 kJ/mol.

Curing Behavior of Epoxy Resin Mixed with Epoxypropoxypropyl Terminated Polydimethylsiloxane

2013 ◽  
Vol 677 ◽  
pp. 197-200
Author(s):  
Zheng Xi ◽  
Jin Dian Ding ◽  
Wen Jun Gan ◽  
Zhao Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Bisphenol A ◽  
Microphase Separation ◽  
Curing Kinetics ◽  
Diglycidyl Ether ◽  
Separation Mechanism ◽  
Scanning Calorimetry ◽  
Modified Epoxy ◽  
Epoxy Systems ◽  
Electronic Microscope

Diglycidyl ether of bisphenol A (DGEBA) and epoxypropoxypropyl terminated polydimethylsiloxane (ETDMS) were mixed in different proportion. The morphology of ETDMS modified epoxy systems was observed by scanning electronic microscope (SEM). Curing kinetics was also studied by differential scanning calorimetry (DSC). It was suggested that the formation of the microstructures followed reaction-induced microphase separation mechanism.

scholarly journals Using the Coats-Redfern Method during Thermogravimetric Analysis and Differential Scanning Calorimetry Analysis of the Thermal Stability of Epoxy and Epoxy/Silica Nanoparticle Nanocomposites

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Subhi A. Al-Bayaty ◽  
Raheem A.H. Al-Uqaily ◽  
Najwa J. Jubier
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Heating Rate ◽  
Silica Nanoparticle ◽  
Frequency Factor ◽  
Inert Atmosphere ◽  
Diffusion Control ◽  
Scanning Calorimetry

In this paper, we provide a study of the thermal decomposition behavior of epoxy and epoxy/silica nanoparticle nanocomposites by using thermogravimetric analysis and differential scanning calorimetry techniques at temperatures ranging from 25°C to 600°C, using a constant heating rate of 10°C per minute under inert atmosphere. With increasing silica nanoparticle percentages of 2%, 4%, 6% and 8%, the kinetic parameters of the activation energy, frequency factor, and thermodynamics property were determined at conversion ranges between 20% to 80% using the Coats-Redfern method for diffusion control reaction (Janders) model. The Arrhenius equation for epoxy decomposition at a heating rate of 10°Cper minute equaled 5.7278x e185.984/RT. Thermal decomposition occurred through two stages: (1) with volatile removal and (2) with a random chain break. The effects of variation of silica nanoparticle percentages on glass transition temperature was investigated. The activation energy, frequency factor, rate constant, and other thermodynamic properties increased with additional silica nanoparticle content due to more bonding, as it needed more heat to break.

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