Prediction and Analysis on Chemorheology of MeHHPA/Hydantoin Epoxy Resin

2017 ◽  
Vol 727 ◽  
pp. 497-502
Author(s):  
Ya Quan Xin ◽  
Ling Li ◽  
Li Yuan Fan
Keyword(s):  
Experimental Data ◽  
Epoxy Resin ◽  
Good Accuracy ◽  
Viscosity Model ◽  
Curing Process ◽  
Ann Model ◽  
Scanning Calorimetry ◽  
Low Viscosity ◽  
Different Temperatures ◽  
Hidden Neurons

Hydantoin epoxy resin, with a hydantoin group, is a kind of low viscosity nitrigen-containing epoxy resin. We prepared methyl hexahydrophalic anhydride (MeHHPY)/ hydantin epoxy resin, in which MeHHPA was used as cure agent. Non-isothermal differential scanning calorimetry was examined to follow the curing process. The variation of viscosity was measured the isothermal curing process by rotating viscometer respectively (70-90°C). A viscosity model, which parameters were determined by Arrhenius equation, was established on the basis of experimental data at three different temperatures. As the result showed, there is a minimum deviation comparing the dual Arrhenius viscosity model data and experimental data in the temperature range of this research. The potential of artificial neural network techniques (ANN) was employed to analyze and predict the chemorheological behavior of MeHHPA/hydatoin epoxy resin. A three layer feed forward ANN model having two input neurons, one output neuron and fourteen hidden neurons was developed to predict the chemorheologica behaviour of MeHHPA/hydatoin epoxy resin. The learning of ANN was accomplished by a backpropagation algorithm. The results display that prediction model has very good accuracy in the process of the whole experiment. Through the established ANN model, the variation characteristic of viscosity can be exactly predicted. Studying on chemorheology by ANN model can help to formulate and optimize technical process.

scholarly journals Fluorescence investigation of epoxy resin LG 285 and mathematical description of the curing process

2019 ◽  
Vol 292 ◽  
pp. 01025
Author(s):  
Michaela Mikuličová ◽  
Vladimír Vašek ◽  
Vojtěch Křesálek
Keyword(s):  
Steady State ◽  
Fluorescence Spectroscopy ◽  
Epoxy Resin ◽  
Mathematical Description ◽  
Curing Process ◽  
Steady State Fluorescence ◽  
Two Component ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Steady State Fluorescence Spectroscopy

In this paper, steady-state fluorescence spectroscopy is used to investigate the curing of two-component epoxy resin LG 285. Moreover, the process of curing is mathematically described. The mixture of resin and hardener HG 287 is measured at five different temperatures (50 °C, 60 °C, 70 °C, 80 °C and 90 °C) for five and a half hours. The results indicate that the process of curing of epoxy resin decelerates with time and accelerates with increasing temperature. Furthermore, the energy of the barrier is calculated.

scholarly journals Curing Kinetics, Mechanical Properties and Thermomechanical Analysis of Carbon Fiber/epoxy Resin Laminates with Different Ply Orientations

2021 ◽  
Author(s):  
Chenglin Zhang ◽  
Guohua Gu ◽  
Shuhua Dong ◽  
Zhitao Lin ◽  
Chuncheng Wei ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Composite Laminates ◽  
Bending Strength ◽  
Fiber Composite ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
The Impact ◽  
Carbon Fiber Epoxy

Abstract In this study, the nonisothermal differential scanning calorimetry (DSC) was carried out to evaluate the curing reaction of fiber/epoxy laminates. The optimal curing process of the prepreg was obtained by T-β extrapolation method and nth-order reaction curing kinetic equation. The bending strength, impact strength and thermodynamic properties of the composite laminates with different ply orientations were investigated, respectively. The results show that the apparent activation energy and the reaction order of the prepregs are 82.89 kJ/mol and 0.92, respectively. The curing process of carbon fiber/epoxy resin prepreg is 130 ℃ /60min + 160 ℃/30 min. The bending strength of [0]10 laminate is 1948.3 MPa, which is 11.8 times higher than that of [+ 45/-45]5s laminate, and 96.4% higher than that of [0/90]5s laminate. The impact strength of [0]10 laminate is higher than that of [+ 45/-45]5s and [0/90]5s laminates. The glass transition temperature (Tg) of the laminates is 142 ~ 146 ℃, and the loss factor of [0]10 laminate is significantly higher than that of [+ 45/-45]5s and [0/90]5s laminates. This research provides a theoretical basis for the further application of prepregs to fiber composite materials.

scholarly journals Construction of a TTT-η Diagram of High-Refractive Polyurethane Based on Curing Kinetics

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3474
Author(s):  
Shidi Huang ◽  
Guiming Zhang ◽  
Weiping Du ◽  
Huifang Chen
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Gelation Time ◽  
Curing Kinetics ◽  
Processing Parameters ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Different Temperatures ◽  
Temperature Transformation

A time–temperature–transformation–viscosity (TTT-η) diagram can reflect changes in the physical states of a resin, which take on significance for the study of the curing process of polyurethane resin lenses. Coupling the differential scanning calorimetry (DSC) test, the curing kinetic parameters of 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI)/2,3-bis((2-mercaptoethyl)thio)-1-propanethiol (BES) polyurethane system were obtained. By phenomenological modeling, the relationships between degree, temperature, and time were obtained. An isothermal DSC test was carried out at 423 K. Based on the DiBenedetto equation, the relationships between glass transition temperature, degree of cure, and time were obtained, and the glass transition temperature was thus correlated with temperature and time. The gelation time at different temperatures was measured by rotary rheometry, and the relationship between gelation time and gelation temperature was established. The time–temperature–transformation (TTT) diagram of H6XDI/BES system was constructed accordingly. Subsequently, a six-parameter double Arrhenius equation was used as the basis for the rheological study. The viscosity was examined during the curing process. The TTT-η diagram was obtained, which laid the theoretical foundation for the optimization and setting of processing parameters.

Studies of the Physical Properties of Cycloaliphatic Epoxy Resin Reacted with Anhydride Curing Agents

2017 ◽  
Vol 737 ◽  
pp. 248-255 ◽  
Author(s):  
Tae Hee Kim ◽  
Dae Yeon Kim ◽  
Choong Sun Lim ◽  
Bong Kuk Seo
Keyword(s):  
Physical Properties ◽  
Reaction Kinetics ◽  
Epoxy Resin ◽  
High Performance ◽  
Industrial Applications ◽  
Scanning Calorimetry ◽  
Low Viscosity ◽  
High Performance Polymer ◽  
Curing Agents ◽  
The Impact

The preparation of high performance epoxy composites for industrial applications has been extensively researched. In this report, we study the change in physical properties and reaction kinetics between epoxy resin and curing agents of similar geometry. For the experiments, celloxide 2021P, an epoxy resin having low viscosity, was blended with three different curing agents: methylhexahydropthalic acid, methyltetrahydropthalic acid, and 5-norbornene-2, 3-dicarboxylic anhydride. The amount of 1, 2-dimethylimidazole catalyst was controlled, and the highest heat flow temperature (Tpeak) was observed at around 145 °C. The impact on reaction kinetics relative to the change in heating rate was studied with differential scanning calorimetry (DSC) for each of the curing agents. The glass transition temperature (Tg) of each composition was measured with a second DSC cycle. The prepared epoxy compositions were thermally cured in a metallic mold to provide pure epoxy resins without fillers. Finally, the flexural strengths of these resins were compared to each other. The authors believe that insights into choosing an appropriate epoxy binder are useful when it comes to the overall preparation of high performance polymer composites.

scholarly journals Exploring instantaneous micro-imprinting technology on semi-cured epoxy resin coating based on relationship between forming precision and curing degree

2016 ◽  
Vol 22 (1) ◽  
pp. 47-53
Author(s):  
Yuehao Luo ◽  
Robert Smith ◽  
Lork Green
Keyword(s):  
Epoxy Resin ◽  
External Pressure ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Manufacturing Efficiency ◽  
Practical Engineering ◽  
Forming Precision ◽  
Physical And Chemical ◽  
The Relationship ◽  
Micro Dimple

Nano/micro-imprinting technology base on polymer material coating has attracted the increasing attentions throughout the world in the past several decades, and it is progressively developing into the hot topic at present, in which, how to improve the manufacturing efficiency is becoming the urgent issue to be resolved. Polymer?s curing process is exactly complicated and sophisticated, which involves simultaneously performing physical and chemical changes, when the curing reaction reaches certain level, the system will abruptly transform into insoluble, non-melting gel with rapidly increased viscosity and rigidity, which can generate fixed deformation under persistent external pressure. In this paper, the plastic deformation capacity of epoxy resin in the curing process is investigated by the micro-dimple imprinting experiment, and the relationship between forming precision and curing degree is ascertained adopting the DSC (differential scanning calorimetry) method. In addition, the instantaneous micro-imprinting technology based on the micro-grooves is explored, and the experimental results indicate that the forming precision can surpass 90%. The paper will establish a novel avenue to apply the nano/micro imprinting technology into practical engineering.

TECHNOLOGICAL AND OPERATIONAL CHARACTERISTICS OF THE VSE-62 LOW-VISCOSITY EPOXY RESIN WITH INCREASED POT LIFE AND ITS APPLICATION

2021 ◽  
pp. 43-50
Author(s):  
I.V. Terekhov ◽  
◽  
A.I. Tkachuk ◽  
K.I. Donetsky ◽  
R.Yu. Karavaev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
High Strength ◽  
Mechanical Tests ◽  
Curing Process ◽  
Thermomechanical Characteristics ◽  
Low Viscosity ◽  
Operational Characteristics ◽  
Pot Life ◽  
Physical And Chemical

The paper considers the main physical and chemical and thermomechanical characteristics of the VSE-62 epoxy resin. The results of rheological tests of the developed resin in dynamic and isothermal modes, as well as the kinetic parameters of the curing process are presented. They help to determine the technological conditions for obtaining defect-free cured samples. The results of mechanical tests show that this resin’s system is characterized by high values of the glass transition temperature and good mechanical properties at test temperature of 120 °C. The absence of solvents in the composition of the VSE-62 epoxy resin and its low viscosity makes it possible to obtain high-strength materials with reduced porosity.

MD Simulation of Crosslinked Epoxy Resin at Different Temperatures

2012 ◽  
Vol 602-604 ◽  
pp. 747-750
Author(s):  
Miao Zhang ◽  
Ping Yang
Keyword(s):  
Experimental Data ◽  
Epoxy Resin ◽  
Md Simulation ◽  
Md Simulations ◽  
Atomic Scale ◽  
Electronic Packages ◽  
Powerful Method ◽  
Wide Range ◽  
Different Temperatures ◽  
The Cross

Epoxy resin is widely used in many electronic packages, the ability to predict properties of cross linked epoxy resin before experiments will facilitate the process of materials design. Molecular dynamics (MD) is a powerful method that can simulate the materials at atomic scale and it can be used to predict the performance and properties of a wide range of materials. In this work, the properties of the cross-linked epoxy resin compound at high temperature were studies by MD simulations. The relations of the glass transition temperature (Tg) and properties of the cross-linked epoxy resin were investigated. The results show that Tg can be estimated by the plot of non-bond energy at different temperatures, and consist with the experimental data.

scholarly journals Monitoring Strain Response of Epoxy Resin during Curing and Cooling Using an Embedded Strain Gauge

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 172
Author(s):  
Hongyu Dong ◽  
Huiming Liu ◽  
Arata Nishimura ◽  
Zhixiong Wu ◽  
Hengcheng Zhang ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Strain Gauge ◽  
Standard Sample ◽  
Initial Point ◽  
Strain Response ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Temperature Changes ◽  
Epoxy Adhesives ◽  
Cryogenic Application

The present work describes the monitoring system of the real-time strain response on the curing process of epoxy resin from the initial point of curing to the end, and the change in strain during temperature changes. A simple mould was designed to embed the strain gauge, thermometer, and quartz standard sample into the epoxy resin, so that the strain and the temperature were simultaneously measured and recorded. A cryogenic-grade epoxy resin was tested and the Differential Scanning Calorimetry (DSC) was used to analyse the curing process. Based on the DSC results, three curing processes were adopted to investigate their influence on strain response as well as residual strain of the epoxy resin. Moreover, impact strength of the epoxy resin with various curing temperatures were tested and the results indicate that the curing plays a crucial role on the mechanical properties. The method will find cryogenic application of epoxy adhesives and epoxy resin based composites to monitor the strain during the curing process as well as the cryogenic service.

scholarly journals Kinetic Analysis of the Curing Process of Biobased Epoxy Resin from Epoxidized Linseed Oil by Dynamic Differential Scanning Calorimetry

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1279
Author(s):  
Diego Lascano ◽  
Alejandro Lerma-Canto ◽  
Vicent Fombuena ◽  
Rafael Balart ◽  
Nestor Montanes ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Linseed Oil ◽  
Single Step ◽  
Curing Process ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Step Process ◽  
Epoxidized Linseed Oil

The curing process of epoxy resin based on epoxidized linseed oil (ELO) is studied using dynamic differential scanning calorimetry (DSC) in order to determine the kinetic triplet (Ea, f(α) and A) at different heating rates. The apparent activation energy, Ea, has been calculated by several differential and integral isoconversional methods, namely Kissinger, Friedman, Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starink. All methods provide similar values of Ea (between 66 and 69 kJ/mol), and this shows independence versus the heating rate used. The epoxy resins crosslinking is characterized by a multi-step process. However, for the sake of the simplicity and to facilitate the understanding of the influence of the oxirane location on the curing kinetic, this can be assimilated to a single-step process. The reaction model has a high proportion of autocatalytic process, fulfilling that αM is between 0 and αp and αM < αp∞. Using as reference the model proposed by Šesták–Berggren, by obtaining two parameters (n and m) it is possible to obtain, on the one hand, the kinetic parameters and, on the other hand, a graphical comparison of the degree of conversion, α, versus temperature (T) at different heating rates with the average n and m values of this model. The good accuracy of the proposed model with regard to the actual values obtained by DSC gives consistency to the obtained parameters, thus suggesting the crosslinking of the ELO-based epoxy has apparent activation energies similar to other petroleum-derived epoxy resins.

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