Mechanical performance and thermal stability of modified epoxy nanocomposite with low loading of graphene platelets

2021 ◽  
pp. 51812
Author(s):  
Noorshashillawati Azura Mohammad ◽  
Sahrim Hj Ahmad ◽  
Ruey Shan Chen ◽  
Nurul Emi Nor Ain Mohammad
2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  

AbstractAdvanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.


2020 ◽  
pp. 073490412093408
Author(s):  
Wei Yan ◽  
Pu Xie ◽  
Zhengwei Yang ◽  
Guangjin Luo ◽  
Weijiang Huang ◽  
...  

Aluminum phosphates coated sepiolite nanocomposite was fabricated via a simple one-pot heterogeneous precipitation strategy, and the effects of aluminum phosphates on the morphology of aluminum phosphates coated sepiolite were investigated. Moreover, the effect of aluminum phosphates coated sepiolite on the flame-retardant behavior, mechanical properties, and thermal stability of epoxy resin have been discussed. The results indicated that the introduction of only 20 wt% aluminum phosphates coated sepiolite in epoxy resin increased the limited oxygen index from 21.8% to 30.1%, thus the material met the UL-94 V-0 rating. Thermogravimetric analyses revealed that char yield increased in the presence of aluminum phosphates coated sepiolite form thermally stable carbonaceous char. Aluminum phosphates–coated sepiolite could improve the mechanical performance, thermal stability of epoxy resin.


2008 ◽  
Vol 17 (1) ◽  
pp. 096369350801700 ◽  
Author(s):  
Zdeno Špitalský ◽  
Alexander Kromka ◽  
Libor Matějka ◽  
Peter Černoch ◽  
Jana Kovářová ◽  
...  

The epoxy nanocomposites filled with 0.1, 0.5, and 1 wt% nanodiamonds (nanoD) were prepared and their properties were compared with neat epoxy network or epoxy nanocomposite filled with 1 wt% multiwalled carbon nanotubes (MWCNTs). The obtained nanoD-epoxy composites increased significantly thermal stability of prepared nanocomposites in comparison with neat epoxy matrix. The exponential decay of light transmittance with increasing concentration of nanoD in sample was observed. The values of storage modulus G` and glass transition temperature Tg significantly decreased by addition of nanoD to epoxy network. This is caused by inhibition of cross-linking reaction of epoxy- and amino- groups by nanoD.


2016 ◽  
Vol 29 (10) ◽  
pp. 1199-1208 ◽  
Author(s):  
Dezhi Wang ◽  
Xin Wang ◽  
Lizhu Liu ◽  
Chunyan Qu ◽  
Changwei Liu ◽  
...  

Structural materials with excellent toughness, a wide processing window, outstanding mechanical performance, and high thermal stability are highly desired in engineering. This work reports a novel bismaleimide (BMI) resin system fabricated using bis[4-(4-maleimidephen-oxy)phenyl)]propane (BMPP), 1-(2-methyl-5-(2,5-dioxo-2H-pyrrol-1(5 H)-yl) phenyl)-1H-pyrrole-2,5-dione (BTM), and diallyl bisphenol A (DABPA) by a melt method. The behaviors of the BTM/BMPP/DABPA resin were modified by adding vinyl-terminated butadiene acrylonitrile (VTBN) in various amounts. The cured BTM/BMPP/DABPA/VTBN resin system exhibited all of the abovementioned desirable properties. Excellent performance was achieved by the post-cured BMI resin containing 6 phr of VTBN (VTBN-6). The glass transition temperature ( Tg) and the 5% weight loss temperature of VTBN-6 were 278°C and 408°C, respectively. Relative to VTBN-0 (BMI resin without VTBN), the impact strength of cured VTBN-6 (12.32 KJ/m2) improved by 45.6%, and the fracture toughness values, KIC and GIC, increased by 48.7% and 26%, respectively. Moreover, the prepolymer of VTBN-6 exhibited low viscosity over a wide temperature range (70–200°C) under dynamic conditions and for an extended time (70 min; 75% improvement over VTBN-0) in an isothermal test. These results confirm the wide processing window of VTBN-6. The high toughness of the VTBN-containing BMI resin was compatible with other excellent performances of the modified resin.


2013 ◽  
Vol 341-342 ◽  
pp. 153-156
Author(s):  
Fan Xie ◽  
Shu Hua Qi ◽  
Jun Peng Li

Polysulfone modified epoxy resin was chosen as the matrix of composite materials. The epoxy/glass fiber/boron nitride composite materials were prepared by heat press molding. The effect of different size and content of BN on the thermal, mechanical, electrical properties and thermal stability of the composite was investigated. The results showed that thermal conductivity and thermal stability of the composite increased with the content of the BN particles, the thermal conductivity of the composite reached 0.672W/m·K when filled with 1μm BN at 20 wt.%. Impact strength and flexure strength of the composite increased initially and then decreased with the increasing content of BN. The electrical insulating property of the composite remained with the content of 20 wt.% BN.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1354 ◽  
Author(s):  
Shahina Riaz ◽  
Soo-Jin Park

A series of composites was prepared from a diglycidyl ether of bisphenol A (DGEBA) with different graphene filler contents to improve their mechanical performance and thermal stability. Graphene oxide (GO) and GO modified with hexamethylene tetraamine (HMTA) were selected as reinforcing agents. As a latent cationic initiator and curing agent, N-benzylepyrizinium hexafluoroantimonate (N-BPH) was used. The effect of fillers and their contents on the mechanical properties and thermal stability of the composites were studied. Fracture toughness improved by 23% and 40%, and fracture energy was enhanced by 1.94- and 2.27-fold, for the composites containing 0.04 wt.% GO and HMTA-GO, respectively. The gradual increase in fracture toughness at higher filler contents was attributed to both crack deflection and pinning mechanisms. Maximum thermal stability in the composites was achieved by using up to 0.1 wt.% graphene fillers.


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