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

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.

2017 ◽  
Vol 30 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Chao Chen ◽  
Yanxia Li ◽  
Yizhuo Gu ◽  
Min Li ◽  
Zuoguang Zhang

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.


2019 ◽  
Vol 25 (4) ◽  
pp. 478-484
Author(s):  
Haoqing XU ◽  
Yuan FANG ◽  
Aizhao ZHOU ◽  
Pengming JIANG ◽  
Shi SHU ◽  
...  

Epoxy resin insulation paint was prepared with epoxy resin (E44) as binder and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by the differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was investigated by using the phenomenological method, and the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determined. The curing reaction mechanism of paint was ascertained by the dynamic temperature DSC method and IR spectroscopy (FTIR) method. The results show that the Kamal model can be used to describe the curing kinetics of epoxy resin paint, and the total reaction orders increase from 1.30 to 2.14. The two rate constants increase with the increase of the curing temperature. The activation energy is 90.5832 kJ/mol and 68.3733 kJ/mol respectively, and the pre-exponential factors are 6.521 × 1015 s-1 and 6.3807 × 109 s-1. The curing reaction of paint consists of two steps: the first step is the addition reaction of epoxy group and primary amine or secondary amine; the second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl. Epoxy resin insulation paint was prepared with epoxy resin (E44) as binders and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was studied by using the phenomenological method, the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determind. The curing reaction mechanism of paint was ascertained by dynamic temperature DSC method and IR spectrogram (FTIR) method. The results show that the kamal model can be used to describe the curing kinetics of epoxy resin paint, the total reaction orders increase from 1.30 to 2.14. The results also show that the two rate constants increase with increasing curing temperature, The activation energies are 90.5832 kJ/mol and 68.3733 kJ/mol, and the pre-exponential factor are 6.521×1015 s-1 and 6.3807×109 s-1. The curing reaction of paint in two steps, the first step is the addition reaction of epoxy group and primary amine or secondary amine. The second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl.


2014 ◽  
Vol 988 ◽  
pp. 31-35
Author(s):  
Jia Le Song ◽  
Chan Chan Li ◽  
Zhi Mi Zhou ◽  
Chao Qiang Ye ◽  
Wei Guang Li

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.


2013 ◽  
Vol 690-693 ◽  
pp. 1649-1652
Author(s):  
Ai Jie Ma ◽  
Qiu Yu Zhang ◽  
You Qiang Shi

In this paper, 2-phenyl imidazole (2-PZ) microcapsule-type curing agent of epoxy resin were prepared through solvent volatilization with 2-PZ and polymethyl acrylic glycidyl ester (PGMA) as the raw materials. The micro-morphology, shape and structure of the microcapsules were studied by scanning electronic microscope (SEM) and fourier transform infrared spectrum (FT-IR). The curing kinetics of microcapsule curing agent/epoxy resin E-44 curing system were studied using TGA/DSC simultaneous thermal analyzer. Results showed that the preparation method is simple and effective and the prepared 2-PZ microcapsules have smooth surfaces and monodisperse size. And the curing kinetic study of epoxy resin system suggested epoxy resin curing temperature was rising with the increase of heating rate.


2013 ◽  
Vol 762 ◽  
pp. 639-643
Author(s):  
Zhi Min Wan ◽  
Yu Yan Liu ◽  
Hong Jun Kang ◽  
Qi Zhu

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.


2011 ◽  
Vol 211-212 ◽  
pp. 638-642 ◽  
Author(s):  
Ming Shan Yang ◽  
Jian Wei Liu ◽  
Lin Kai Li

Silicon-containing epoxy resin (CNE-Si) was synthesized from diphenylsilandiol (DPSD) and ortho-cresol novolac epoxy resin using SnCl2 as catalyst. The chemical structure of CNE-Si prepared in this paper was characterized by 1H-NMR and FTIR. The thermal stability was analyzed by TGA. The result showed that the –Si- group enhanced the thermal stability of the epoxy resin. The curing kinetics of the system was studied by non-isothermal DSC. The kinetic parameters of the curing reaction including the activation energy were calculated using Kissinger and Ozawa method. The results showed that the system containing CNE-Si has lower curing temperature and more quick curing speed compared to CNE, which can be used for manufacturing the quick-curing EMCs or afterward-curing-free EMCs.


2014 ◽  
Vol 936 ◽  
pp. 28-33 ◽  
Author(s):  
Wei Xing Deng ◽  
Yuan Wei Zhong ◽  
Jie Qin ◽  
Xue Bing Huang ◽  
Jin Wen Peng

A new epoxy resin based on dichlorosilane and 9,9-bis (4-hydroxyphenyl) fluorene was synthesized to produce a highly heat-resistant network. The chemical structure was characterized with FTIR spectroscopy and 1H-NMR. 4-4′-Diaminodiphenylsulfone (DDS) was used as the curing agent. The curing kinetics of different epoxy/DDS systems were investigated using non-isothermal differential scanning calorimetry (DSC). The results showed that the values of activation energy (E) were affected by the chemical structure of epoxy resin, and BPEBF exhibited lower curing reactivity towards DDS compared to E-51.


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