Reduced Time Approach to Curing Kinetics, Part I: Dynamic Rate and Master Curve from Isothermal Data

1993 ◽  
Vol 66 (5) ◽  
pp. 849-864 ◽  
Author(s):  
T. W. Chan ◽  
G. D. Shyu ◽  
A. I. Isayev
Keyword(s):  
Kinetic Data ◽  
Master Curve ◽  
Curing Kinetics ◽  
Isothermal Kinetics ◽  
Scanning Calorimetry ◽  
Rubber Compounds ◽  
Physico Chemical ◽  
Curing Kinetic ◽  
Isothermal Kinetic ◽  
Reduced Time

Abstract A reduced time approach has been used to predict nonisothermal curing kinetics based on isothermal kinetic data. This approach makes it clear that the conversion in a kinetic process is a function of the reduced time alone and allows for the construction of a master curve from isothermal kinetic data, indicating that the dynamic (or nonisothermal ) rate is equal to the isothermal rate. The approach can be applied to curing, crystallization, and other physico-chemical kinetics. A method is also described for correcting the nonisothermal curing kinetic data obtained from differential scanning calorimetry ( DSC ) for a temperature lag between the sample and the DSC furnace. For two rubber compounds, it has been found that the nonisothermal curing kinetic data corrected for this temperature lag are in better agreement with the predictions based on isothermal kinetics than the uncorrected data.

Reduced Time Approach to Curing Kinetics, Part II: Master Curve from Nonisothermal Data

1994 ◽  
Vol 67 (2) ◽  
pp. 314-328 ◽  
Author(s):  
G. D. Shyu ◽  
T. W. Chan ◽  
A. I. Isayev
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Kinetic Data ◽  
Master Curve ◽  
Curing Kinetics ◽  
Reference Temperature ◽  
Scanning Calorimetry ◽  
Kinetic Information ◽  
Wide Range ◽  
Curing Kinetic

Abstract Nonisothermal curing kinetic data obtained from differential scanning calorimetry (DSC) for a rubber compound are corrected for the effects of temperature lag between the DSC sample and furnace. The method of Eder and Janeschitz-Kriegl, which is based on experimental data alone without reference to any kinetic model, is used for these corrections. A method is presented for shifting the corrected nonisothermal curing kinetic data with respect to an arbitrarily chosen reference temperature to obtain a master curve. The method is based on experimental data alone without assuming any specific form of kinetic model. When the isothermal curing kinetic data for the same material are shifted with respect to the same reference temperature, a master curve is also obtained which basically overlaps the corresponding master curve from nonisothermal data. It follows that nonisothermal DSC measurements provide the same curing kinetic information as isothermal ones, only over a wider range of temperatures. The shift factors obtained from experimental data alone are compared with the corresponding values calculated from a kinetic model with an Arrhenius type of temperature dependence. This serves as a means of model evaluation. It is concluded that the kinetic model is good at describing isothermal curing kinetic data. But it yields reliable curing kinetic information over a narrower range of temperatures than nonisothermal data alone without resort to any model. The Arrhenius extrapolation of the limited isothermal data to a wide range of temperatures is quite good.

Study on Curing Kinetics of MEP-15/593/660 System

2014 ◽  
Vol 988 ◽  
pp. 31-35
Author(s):  
Jia Le Song ◽  
Chan Chan Li ◽  
Zhi Mi Zhou ◽  
Chao Qiang Ye ◽  
Wei Guang Li
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Conversion Ratio ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Curing Kinetic ◽  
The Relationship ◽  
Kinetics Of

Curing kinetics of MEP-15/593 system and MEP-15/593/660 system is studied by means of differential scanning calorimetry (DSC). Curing kinetic parameters are evaluated and the relationship between diluent 660 and the curing properties is investigated. The results show that the diluent 660 can not only reduce viscosity and activation energy, but also improve the degree of cure and conversion ratio.

The Preparation and Curing Kinetics of Epoxy/PhS(4, 4'-dihydroxydiphe-nylsulfone)/aluminum tris (tetradecylacetoacetate) Latent Resin System

2013 ◽  
Vol 762 ◽  
pp. 639-643
Author(s):  
Zhi Min Wan ◽  
Yu Yan Liu ◽  
Hong Jun Kang ◽  
Qi Zhu
Keyword(s):  
Reaction Order ◽  
Curing Kinetics ◽  
Kinetic Mechanism ◽  
Resin System ◽  
Scanning Calorimetry ◽  
Aluminum Compound ◽  
Curing Reaction ◽  
Epoxy Resin System ◽  
Curing Kinetic ◽  
Kinetics Of

In this paper, organic aluminum compound, aluminum tris (tetradecylacetoacetate) (Al-14) was synthesized, and its molecular structure was identified by IR spectrum. The investigation of the curing kinetic of epoxy resin system with PhS (4, 4-dihydroxydiphenylsulfone)/aluminum tris (tetradecylacetoacetate) (Al-14) latent catalysts was performed by differential scanning calorimetry (DSC) using an isothermal approach. All kinetic parameters of the curing reaction including the reaction order and activation energy were calculated and reported. The results indicated that the curing reaction of Ep/PhS/Al-14 compand system in this experiment proceeded through an autocatalytic kinetic mechanism.

An improved simplified approach for curing kinetics of epoxy resins by nonisothermal differential scanning calorimetry

2017 ◽  
Vol 30 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Chao Chen ◽  
Yanxia Li ◽  
Yizhuo Gu ◽  
Min Li ◽  
Zuoguang Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Kinetic Parameters ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Scanning Calorimetry ◽  
Simplified Approach ◽  
Curing Kinetic ◽  
Autocatalytic Curing ◽  
Kinetics Of

The curing kinetics of two different types of commercial epoxy resins were investigated by means of nonisothermal differential scanning calorimetry (DSC) in this work. The complex curve of measured heat flow of CYCOM 970 epoxy resin was simplified with the method of resolution of peak. Two typical autocatalytic curing reaction curves were gained and the kinetic parameters of the curing process were demonstrated by combination of those two reactions. The Kissinger method was adopted to obtain the values of the activation energy. The parameters of curing kinetic model were acquired according to the fitting of Kamal model. Isothermal DSC curve of CYCOM 970 epoxy resin obtained using the experimental data shows a good agreement with that theoretically calculated. Then, 603 epoxy resin was investigated by the simplified method and the kinetic parameters were received through the same procedure. The nonisothermal DSC curve tested according to the recommended cure cycle of 603 epoxy resin is also consistent with the calculated results. This improved simplified approach provides an effective method to analyze the curing kinetics of the epoxy resins with complex DSC curves as similar to this study.

scholarly journals The Curing Kinetics of E-Glass Fiber/Epoxy Resin Prepreg and the Bending Properties of Its Products

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4673
Author(s):  
Lvtao Zhu ◽  
Zhenxing Wang ◽  
Mahfuz Bin Rahman ◽  
Wei Shen ◽  
Chengyan Zhu
Keyword(s):  
Glass Fiber ◽  
Epoxy Resin ◽  
Composite Laminates ◽  
Curing Kinetics ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Reinforced Composite ◽  
Curing Kinetic ◽  
Kinetics Of

The curing kinetics can influence the final macroscopic properties, particularly the three-point bending of the fiber-reinforced composite materials. In this research, the curing kinetics of commercially available glass fiber/epoxy resin prepregs were studied by non-isothermal differential scanning calorimetry (DSC). The curing kinetic parameters were obtained by fitting and the apparent activation energy Ea of the prepreg, the pre-exponent factor, and the reaction order value obtained. A phenomenological nth-order curing reaction kinetic model was established according to Kissinger equation and Crane equation. Furthermore, the optimal curing temperature of the prepregs was obtained by the T-β extrapolation method. A vacuum hot pressing technique was applied to prepare composite laminates. The pre-curing, curing, and post-curing temperatures were 116, 130, and 153 °C respectively. In addition, three-point bending was used to test the specimens’ fracture behavior, and the surface morphology was analyzed. The results show that the differences in the mechanical properties of the samples are relatively small, indicating that the process settings are reasonable.

Curing kinetics study of epoxy resin/hyperbranched poly(amideamine)s system by non-isothermal and isothermal DSC

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Zhang ◽  
Hui Kang Yang ◽  
Guang Shi
Keyword(s):  
Kinetic Model ◽  
Epoxy Resin ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Scanning Calorimetry ◽  
Fitting Procedure ◽  
Hyperbranched Poly ◽  
Numerical Process ◽  
Isothermal Kinetic ◽  
Dsc Method

AbstractCuring kinetics of epoxy resin/hyperbranched poly(amide amine)s (HPAMAM) system was studied by non-isothermal and isothermal differential scanning calorimetry (DSC). Non-isothermal DSC scans indicated that H-PAMAM was an effective curing agent of epoxy resin. The apparent activation energy (E) was 54.3 kJ/mol calculated through Kissinger method, and the kinetic parameters were determined by Málek method for the kinetic analysis of the thermal treatment obtained by DSC measurement. A two-parameter (m, n) autocatalytic model (Sěsták-Berggren equation) was found to be the most adequate selected kinetic model. In addition, the predicted curves from the kinetic model fit well with the nonisothermal DSC thermogram. The isothermal DSC method was used to investigate the curing process for resin at 60, 65, 70, 75 and 80 °С, respectively. Isothermal kinetic parameters, including k1, k2, m and n, were determined based on an autocatalytic mechanism proposed by Kamal. Both models were validated for a fitting to the experimental data by the Levenberg-Marquardt method. A process to determine the initial values for the fitting procedure was also proposed. The predictions of the validated models were in good agreement with the measured data, and were therefore applicable for numerical process optimization

scholarly journals Synthesis of Novel Benzoxazines Containing Sulfur and Their Application in Rubber Compounds

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1262
Author(s):  
Acerina Trejo-Machin ◽  
João Paulo Cosas Fernandes ◽  
Laura Puchot ◽  
Suzanne Balko ◽  
Marcel Wirtz ◽  
...  
Keyword(s):  
Phenolic Resin ◽  
Condensation Reaction ◽  
Curing Kinetics ◽  
Structural Features ◽  
Rubber Compound ◽  
Scanning Calorimetry ◽  
Phenolic Resins ◽  
Rubber Compounds ◽  
Mannich Condensation ◽  
13C Nuclear Magnetic Resonance

This work reports the synthesis and successful use of novel benzoxazines as reinforcing resins in polyisoprene rubber compounds. For this purpose, three new dibenzoxazines containing one (4DTP-fa) or two heteroatoms of sulfur (3DPDS-fa and 4DPDS-fa) were synthesized following a Mannich condensation reaction. The structural features of each benzoxazine precursor were characterized by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and Raman. The new precursors showed well suited reactivity as characterized by differential scanning calorimetry (DSC) and rheology and were incorporated in rubber compounds. After the mixing, the curing profiles, morphologies and mechanical properties of the materials were tested. These results show that the structural feature of each isomer was significantly affecting its behavior during the curing of the rubber compounds. Among the tested benzoxazines, 3DPDS-fa exhibited the best ability to reinforce the rubber compound even compared to common phenolic resin. These results prove the feasibility to reinforce rubber compounds with benzoxazine resins as a possible alternative to replace conventional phenolic resins. This paper provides the first guide to use benzoxazines as reinforcing resins for rubber applications, based on their curing kinetics.

Comparison of the Isothermal and Non-Isothermal Kinetics for Predicting the Thermal Hazard of Tert-Butyl Peroxybenzoate

2011 ◽  
Vol 328-330 ◽  
pp. 124-127 ◽  
Author(s):  
Chun Ping Lin ◽  
Yi Ming Chang ◽  
Jo Ming Tseng ◽  
Mei Li You
Keyword(s):  
Kinetic Equations ◽  
Organic Peroxide ◽  
Decomposition Temperature ◽  
Isothermal Kinetics ◽  
Thermal Activity ◽  
Thermal Hazard ◽  
Scanning Calorimetry ◽  
Tert Butyl ◽  
Isothermal Kinetic ◽  
Thermal Activity Monitor Iii

Tert-butyl peroxybenzoate (TBPB), a liquid organic peroxide, has been widely employed in the petrifaction industry as a polymerization formation agent. This study investigated the thermokinetic parameters of TBPB by isothermal kinetic algorithms and non-isothermal kinetic equations, using thermal activity monitor III (TAM III) and differential scanning calorimetry (DSC), respectively. Simulations of 0.5 L, 25 kg, 55 gallon, and 400 kg reactors in liquid thermal explosion models were performed. It is based on the thermal hazard properties, such as the heat of decomposition (∆Hd), activation energy (Ea), self-accelerating decomposition temperature (SADT), control temperature (CT), emergency temperature (ET), and critical temperature (TCR). From the experimental results, the optimal conditions to avoid violent runaway reactions during the storage and transportation of TBPB were determined.

Preparation and Non-Isothermal Kinetics Analysis of N-[(4-Bromo-3,5-Difluorine)Phenyl]acrylamide

2013 ◽  
Vol 781-784 ◽  
pp. 580-584
Author(s):  
Xin Ding Yao ◽  
Rui Na Fang ◽  
Hong Jian Pang ◽  
Zong Wu Wang ◽  
Guo Ji Liu
Keyword(s):  
Kinetic Data ◽  
Isothermal Kinetics ◽  
Acryloyl Chloride ◽  
Kinetics Analysis ◽  
Exponential Factor ◽  
Chemical Reaction Mechanism ◽  
Ozawa Equation ◽  
Mechanism Function ◽  
Isothermal Kinetic ◽  
First Time

N-[(4-bromo-3,5-difluorine) phenyacrylamide was synthesized first time by the interaction of 4-Bromo-3,5-difluoroaniline with acryloyl chloride in presence of triethylamine. The compound behavior was investigated using TG and DSC techniques under non-isothermal linear regime. The non-isothermal kinetic data were analyzed with the Achar equation, Coats-Redfern equation,Kissinger equation, Flynn-Wall-Ozawa equation and Starink equation. The mechanism function and kinetic parameters of the thermal decomposition were obtained. The chemical reaction mechanism (F3) controlled the decomposition process. The apparent activation energy and the pre-exponential factor wereE=240.01 KJmol-1andA=2.341023s-1respectively.

scholarly journals Thermal and Photocatalytic Performance of Unsaturated Polyester Resins Modified with TiO2 Nanoparticles as Panel Bodies for Vehicles

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2036
Author(s):  
Miren Blanco ◽  
Cristina Monteserín ◽  
Nerea Uranga ◽  
Estíbaliz Gómez ◽  
Estíbaliz Aranzabe ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Energy Use ◽  
Near Infrared ◽  
Uv Light ◽  
Unsaturated Polyester ◽  
Curing Kinetics ◽  
Pollutant Emissions ◽  
Transport Sector ◽  
Scanning Calorimetry ◽  
Photocatalytic Effect

The transport sector is the fastest growing contributor to climate emissions and experiences the highest growth in energy use. This study explores the use of TiO2 nanoparticles for obtaining photocatalytic nanocomposites with improved infrared reflectance properties. The nanocomposites were prepared by dispersing 0–20 wt% of TiO2 nanoparticles in an unsaturated polyester resin. The effect of TiO2 on the curing kinetics was studied by differential scanning calorimetry, showing a significant delay of the curing reactions. The thermal reflectance of the modified resins was characterized by UV-Vis-NIR spectrophotometry, measuring total solar reflectance (TSR). The TiO2 greatly increased the TSR of the resin, due to the reflectance properties of the nanoparticles and the change in color of the modified resin. These nanocomposites reflect a significant part of near-infrared radiation, which can contribute to a reduction of the use of heating, ventilation, and air conditioning. Moreover, the photocatalytic effect of the TiO2 modified nanocomposites was studied by monitoring the degradation of an organic model contaminant in an aqueous medium under UV light, and the reusability of the nanocomposites was studied with 5 cycles. The developed nanocomposites are proposed as a solution for reducing global warming and pollutant emissions.

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