Curing Kinetics Analysis and Properties Researches of Cyanate Composites

2014 ◽  
Vol 893 ◽  
pp. 205-208
Author(s):  
Jing Dang ◽  
Li Yang ◽  
Wen Han
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Dielectric Constant ◽  
Infrared Spectroscopy ◽  
Curing Kinetics ◽  
Kinetics Analysis ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Comprehensive Properties ◽  
Kinetics Of ◽  
Gelation Test

The powdery nitrile butadiene rubbers (P-NBRs) are employed to improve the comprehensive properties of the bisphenol A dicyanate ester (BADCY). The addition of P-NBRs affecting on the curing kinetics of the composites is analyzed and characterized by gelation test, differential scanning calorimentry (DSC) and Fourier transformed infrared spectroscopy (FTIR). And the contents of P-NBRs affecting on the mechanical and dielectric properties of the P-NBRs/BADCY composites are also investigated. Results show that the addition of P-NBRs has little influence on the cure activation energy. The mechanical properties of the P-NBRs/BADCY composites are optimal with 5 wt% P-NBRs. The dielectric constant values of the P-NBRs/BADCY composites are increased with the increasing addition of P-NBRs.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

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.

scholarly journals Mechanical properties and curing kinetics of epoxy resins cured by various amino-terminated polyethers

2010 ◽  
Vol 28 (6) ◽  
pp. 961-969 ◽  
Author(s):  
Li-ying Zhao ◽  
Jian-guo Guan ◽  
Hui-ru Ma ◽  
Zhi-gang Sun
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Kinetics Of

scholarly journals ISOTHERMAL CURING KINETICS OF POLYMETHACRYLIMIDE/NANO-SiO2 COMPOSITES BASED ON A DYNAMIC THERMOMECHANICAL ANALYSIS

2021 ◽  
Vol 55 (2) ◽  
pp. 293-304
Author(s):  
Jing Zhang ◽  
Yi-min Wu ◽  
Xu Ma ◽  
Bao-Yu Huang ◽  
Song Lv ◽  
...  
Keyword(s):  
Activation Energy ◽  
Integral Method ◽  
Model Fitting ◽  
Curing Kinetics ◽  
Thermomechanical Analysis ◽  
Avrami Model ◽  
Nano Sio2 ◽  
Friedman Method ◽  
Kinetics Of ◽  
Relative Conversion

The isothermal curing kinetics of polymethacrylimide/nano-SiO2 composites were investigated using a dynamic thermomechanical analysis. The relative conversion was defined with the storage modulus. The Avrami model-fitting method, Friedman method and integral method were applied to analyze the curing kinetics. The storage modulus and loss modulus increased appreciably, spanning three orders of magnitude throughout the curing. The frequency correlation of the relative conversion was noticeable at 180 °C because the glass transition took place when the curing degree was not high enough. The Avrami model-fitting analysis gave good fits for the experimental data. The activation energy calculated with the Avrami equation changed from 65.46 kJ/mol to 25.28 kJ/mol at 180–190 °C, while at 190–200 °C, the activation energy changed from 107.14 kJ/mol to 63.82 kJ/mol. The model-free analysis revealed the dependence of the activation energy on the relative conversion. The activation energy increased from 104.3 kJ/mol to 130.6 kJ/mol with the use of the Friedman method when the relative conversion ranged between 0.4–0.8. Similarly, the activation energy calculated with the integral method increased from 71.5 kJ/mol to 103.4 kJ/mol. When the relative conversion exceeded 0.8, the activation energy decreased gradually. The mobility of the reactive groups was hindered and the crosslinking density of the composite was much higher. The curing kinetics became diffusion controlled. The activation energy of the PMI/SiO2 composite was greater than that of PMI, which could be attributed to the hindrance effect caused by nano-SiO2.

scholarly journals Photo-curing kinetics of hydroxyethyl acrylate (HEA): synergetic effect of dye/amine photoinitiator systems

2019 ◽  
Vol 11 (1) ◽  
pp. 1-9
Author(s):  
Nouria Bouchikhi ◽  
Manel Bouazza ◽  
Salah Hamri ◽  
Ulrich Maschke ◽  
Djahida Lerari ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Synergetic Effect ◽  
Curing Kinetics ◽  
Ftir Analysis ◽  
Light Conditions ◽  
Total Conversion ◽  
Photo Curing ◽  
Kinetics Of

AbstractThe aim of this study is to examine and evaluate several dye/amine systems as photoinitiators for photopolymerization of 2-hydroxyethyl acrylate (HEA) monomer under visible light conditions. For this purpose, a series of dye/amine photoinitiators were formed using methylene blue (MB) or acridine orange (AO) as photosensitizers, and triethanolamine (TEOA), ethyl 4-(dimethylamino) benzoate (EDMAB), trioctylamine (TOA), and N,N-diméthylallylamine (DMAA) as co-initiators. The photopolymerization kinetic of the HEA monomer in the presence of proposed dye/amine systems was performed using Fourier-transform infrared spectroscopy (FTIR) analysis and the synergetic effect of the dye/amine photoinitiators systems on the photopolymerization efficiency was examined. Interestingly, (MB/EDMAB) system shows the better reactivity with a total conversion of HEA monomer.

Influence of carbon nanofillers on the curing kinetics of epoxy-amine resin

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90437-90450 ◽  
Author(s):  
L. Vertuccio ◽  
S. Russo ◽  
M. Raimondo ◽  
K. Lafdi ◽  
L. Guadagno
Keyword(s):  
Activation Energy ◽  
Curing Kinetics ◽  
Isoconversional Method ◽  
Epoxy Amine ◽  
Carbon Nanofillers ◽  
Advanced Isoconversional Method ◽  
Kinetics Of

Variation of the activation energy with conversion obtained by “advanced isoconversional method”.

Flame retardant, mechanical properties and curing kinetics of DOPO-based epoxy resins

2014 ◽  
Vol 109 ◽  
pp. 218-225 ◽  
Author(s):  
Jianhua Hu ◽  
Jiye Shan ◽  
Dehua Wen ◽  
Xinxing Liu ◽  
Jianqing Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resins ◽  
Curing Kinetics ◽  
Kinetics Of
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