Investigating the relationship between tack and degree of conversion in DGEBA-based epoxy resin cured with dicyandiamide and diuron

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Kuliaei ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Epoxy Resin ◽  
Reaction Order ◽  
Theoretical Data ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Degree Of Conversion ◽  
Ozawa Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Kinetics Of

Abstract The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$ ). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing.

Cure Kinetics of Epoxy/DDS/ Epoxy-Grafted Nano-Aluminum Oxide

2011 ◽  
Vol 236-238 ◽  
pp. 2058-2062
Author(s):  
Hong Jun Zhou ◽  
Guo Qiang Yin ◽  
Miao Hong Zhuang ◽  
Jian Fang Ge ◽  
Xuan Lin
Keyword(s):  
Aluminum Oxide ◽  
Epoxy Resins ◽  
Cure Kinetics ◽  
Ozawa Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Autocatalytic Model ◽  
Chain Mobility ◽  
Málek Method ◽  
Kinetics Of

The cure kinetics of epoxy/epoxy-grafted nano-aluminum oxide using 4, 4'-diaminodiphenylsulphone (DDS) as the curing agent was studied by nonisothermal differential scanning calorimetry (DSC) at different heating rates. The activation energy (Ea) was determined by Flynn-Wall-Ozawa method, and kinetic model was predicted by Málek method. TheEa values of epoxy/nano-aluminum oxide/DDS systems are generally higher than those of epoxy /DDS. These imply that the addition of nano-aluminum oxide would inhibit the chain mobility of the epoxy resins. Furthermore, autocatalytic model was found to be appropriate to describe the kinetics of above mentioned reactions. The predicted curves fit well with the experimentally obtained curves.

Kinetics of the Curing Reaction of a Diglycidyl Ether of Bisphenol with a Methanol Etherified Amino Resin

2011 ◽  
Vol 380 ◽  
pp. 60-63 ◽  
Author(s):  
Yong Lv ◽  
Zhu Long ◽  
Shi Yong Luo ◽  
Lei Dai
Keyword(s):  
Cure Kinetics ◽  
Frequency Factor ◽  
Diglycidyl Ether ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Before And After ◽  
Amino Resin ◽  
Chemical Products ◽  
Kinetics Of

Subscript text Subscript textEpoxy resins have been widely used for inner coating in food can and other chemical products storage containers. Differential scanning calorimetry (DSC) was used at different heating rates to study the cure kinetics of the diglycidyl ether of bisphenol A (DGEBA) with a methanol etherified amino resin (MEAR). The apparent activation energy derived from Kissinger and Ozawa methods is 35.67KJ/mol and 40.27kJ/mol, respectively. The reaction order evaluated by Crane equation is 0. 95 and the frequency factor is 1.12×104s-1. Reaction mechanism was monitored by FTIR spectra of the reaction mixtures before and after curing. The curing reaction below 200°C is between alkoxylmethyl (>NCH2OCH3) and epoxide group, not between alkoxylmethyl and hydroxyls.

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.

Effects of additives on the cure kinetics of vinyl ester pultrusion resins

2021 ◽  
pp. 002199832110015
Author(s):  
Alexander Vedernikov ◽  
Yaroslav Nasonov ◽  
Roman Korotkov ◽  
Sergey Gusev ◽  
Iskander Akhatov ◽  
...  
Keyword(s):  
Vinyl Ester ◽  
Mean Squared Error ◽  
Cure Kinetics ◽  
Zinc Stearate ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Different Temperatures ◽  
Predicted Values ◽  
Kinetics Of ◽  
Final Degree

Pultrusion is a highly efficient composite manufacturing process. To accurately describe pultrusion, an appropriate model of resin cure kinetics is required. In this study, we investigated cure kinetics modeling of a vinyl ester pultrusion resin (Atlac 430) in the presence of aluminum hydroxide (Al(OH)3) and zinc stearate (Zn(C18H35O2)2) as processing additives. Herein, four different resin compositions were studied: neat resin composition, composition with Al(OH)3, composition comprising Zn(C18H35O2)2, and composition containing both Al(OH)3 and Zn(C18H35O2)2. To analyze each composition, we performed differential scanning calorimetry at the heating rates of 5, 7.5, and 10 K/min. To characterize the cure kinetics of Atlac 430, 16 kinetic models were tested, and their performances were compared. The model based on the [Formula: see text]th-order autocatalytic reaction demonstrated the best results, with a 4.5% mean squared error (MSE) between the experimental and predicted data. This study proposes a method to reduce the MSE resulting from the simultaneous melting of Zn(C18H35O2)2. We were able to reduce the MSE by approximately 34%. Numerical simulations conducted at different temperatures and pulling speeds demonstrated a significant influence of resin composition on the pultrusion of a flat laminate profile. Simulation results obtained for the 600 mm long die block at different die temperatures (115, 120, 125, and 130 °C) showed that for a resin with a final degree of cure exceeding 95% at the die exit, the maximum difference between the predicted values of pulling speed for a specified set of compositions may exceed 1.7 times.

scholarly journals Dynamic Cure Kinetics and Physical-Mechanical Properties of PEG/Nanosilica/Epoxy Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Haleh Nowruzi Varzeghani ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Solid Particles ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Cure Kinetic ◽  
Cure Temperature ◽  
Kinetics Of

This study investigated the effect of polyethylene glycol (PEG) and nanosilica (NS) on the physical-mechanical properties and cure kinetics of diglycidyl ether of bisphenol-A-based epoxy (DGEBA-based EP) resin. For this purpose, tensile and viscometry tests, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC) were carried out under dynamic conditions. The results showed that adding NS and PEG enhances the maximum cure temperature as well as the heat of cure reaction (ΔH) in EP-NS, while it decreases in EP-PEG and EP-PEG-NS. The cure kinetic parameters of EP-PEG-NS were calculated by Kissinger, Ozawa, and KSA methods and compared with each other. The Ea calculated from the Kissinger method (96.82 kJ/mol) was found to be lower than that of the Ozawa method (98.69 kJ/mol). Also, according to the KAS method, the apparent Ea was approximately constant within the 10-90% conversion range. Tensile strength and modulus increased by adding NS, while tensile strength diminished slightly by adding PEG to EP-NS. The glass transition temperature (Tg) was calculated using DMTA which was increased and decreased by the addition of NS and PEG, respectively. The results of the viscometry test showed that the viscosity increased with the presence of both PEG and NS and it prevented the deposition of solid particles.

scholarly journals Investigation on cure kinetics of epoxy resin containing carbon nanotubes modified with hyper-branched polyester

RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29830-29839 ◽  
Author(s):  
Li Lu ◽  
Liao Xia ◽  
Hao Zengheng ◽  
Sheng Xingyue ◽  
Zhang Yi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Cure Kinetics ◽  
Scanning Calorimetry ◽  
Kinetics Of

The cure kinetics of epoxy resin cured by D-EP, D-EP/CNT composites and D-EP/CNTs-H20 were investigated by non-isothermal differential scanning calorimetry (DSC).

Isothermal cure kinetics of a diglycidyl ether of bisphenol A/1,3-bisaminomethylcyclohexane (DGEBA/1,3-BAC) epoxy resin system

1995 ◽  
Vol 56 (9) ◽  
pp. 1029-1037 ◽  
Author(s):  
L. Barral ◽  
J. Cano ◽  
A. J. López ◽  
J. López ◽  
P. Nogueira ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Epoxy Resin ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Resin System ◽  
Isothermal Cure ◽  
Epoxy Resin System ◽  
Kinetics Of
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