scholarly journals Mechanical, Thermal, and Electrical Properties of BN–Epoxy Composites Modified with Carboxyl-Terminated Butadiene Nitrile Liquid Rubber

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1548 ◽  
Author(s):  
Xingming Bian ◽  
Rui Tuo ◽  
Wei Yang ◽  
Yiran Zhang ◽  
Qing Xie ◽  
...  

Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high voltage insulation. In this work, carboxyl-terminated butadiene nitrile liquid rubber (CTBN) was used to toughen the boron nitride-epoxy hybrid system, and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated. The results showed that when the content of CTBN was 5–15 wt.%, the CTBN formed a dispersed island structure in the epoxy resin matrix. The toughness of the composite increased by about 32%, the breakdown strength was improved, and the thermal conductivity was about 160% higher than that of pure epoxy resin. As the CTBN content increased, the glass transition temperature and thermal stability of the composite decreased and the dielectric constant and the dielectric loss increased. When the CTBN content is 10–15 wt.%, a toughened epoxy composite material with better comprehensive properties is obtained.

2020 ◽  
Vol 1003 ◽  
pp. 173-178
Author(s):  
Chen Liu ◽  
Hao Ran Zhou ◽  
Zhen Yuan

Boron nitride (BN) was modified by silane coupling agent (KH560) and used as heat conductive filler to prepare the modified BN (BN560)/epoxy composite. The effect of the BN560 filler content on the thermal conductivity and thermal stability of the epoxy composite was studied. The results show that BN560 can be uniformly dispersed in the epoxy matrix by an ultrasonic disperser. The BN560 added can effectively improve the thermal conductivity of the epoxy composite. With the increase of BN560 content to 20 wt.%, the thermal conductivity of the composite increases accordingly to 0.27 W/(m·K), 50% higher than that of pure epoxy, and a heat conductive network is formed. The BN560 added can improve the thermal stability of the composite. With increasing BN560 content, the thermal decomposition temperature and glass transition temperature of the composite increase. The composite with the BN560 content of 20 wt.% has the weight loss of 10 wt.% at 395.12 °C and the glass transition temperature of 144.59 °C.


2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.


2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000196-000200 ◽  
Author(s):  
Kenji Okamoto ◽  
Yuji Takematsu ◽  
Miyako Hitomi ◽  
Yoshinari Ikeda ◽  
Yoshikazu Takahashi

There is a demand to improve the thermal stability of epoxy molding resins used in the power module of SiC power chips operating at temperatures of 200°C or more. This paper describes a technique for increasing the thermal stability of the resin by decreasing molecular motion through the addition of nanofiller. The experimental results showed that the glass transition temperature (Tg) of the epoxy resin increased by approximately 30°C when the silica nanofiller was added. The epoxy resin added nanofiller was investigated in order to achieve the operation temperature 200°C of power module.


2013 ◽  
Vol 853 ◽  
pp. 28-33
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen ◽  
Kung Liang Lin ◽  
Bor Kae Chang

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the chemical resistance, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The chemical resistance of the nanocomposite specimens is compared with that of pure glass fiber/epoxy composite specimens when tested in acetone. The results show that the addition of 2 wt.% SiO2 increases the value of storage modulus by 1646MPa compared to that of the sample containing no silica nanopowder. Following immersion in acetone, all the nanocomposite specimen storage modulus decreased, but the addition of SiO2 reduced the decline, where the 2 wt. % samples decrease from 11.76% reduction to 0.84% and no significant change in the Tg compared to that of the sample with no silica nanopowder. Therefore, the experimental results indicate that 2 wt.% SiO2 addition is beneficial in improving chemical resistance, glass transition temperature, and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.


2013 ◽  
Vol 787 ◽  
pp. 408-412
Author(s):  
Jiao Yan Ai ◽  
Quan Chen ◽  
Xiao Bo Wang

Two kinds of polyester bis (p-hydroxybenzoic acid) butanediolatepolyester (BDPET) and bis (p-hydroxybenzoic acid) diethylene glycol (DGPET) were synthesized through melting transesterification reaction.Then the epoxy resins were modified with BDPET or DGPET,and nanoTiO2. The composites were characterized by DSC and SEM. The experimental results showed that the polyester can act as an effective toughening modifier for the epoxy resin. The mechanical properties of the composites were greatly improved and reached to the maxium at 4wt.%PET. The PET/EP system modified by adding suitable amount of nanoTiO2have better performance.The glass transition temperature (Tg) of PET/EP and nanoTiO2/PET/EP system improved about 20°Cand 27.8°C,respectively.


2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Mahesh Baboo ◽  
Manasvi Dixit ◽  
Dinesh Patidar ◽  
Kananbala Sharma ◽  
Narendra Sahai Saxena

Abstract This paper focuses on the comparative evaluation of the glass transition temperature (Tg), storage modulus and thermal conductivity of trans-polyisoprene (TPI) and CdS-TPI nanocomposite. The CdS nanoparticles synthesized by chemical route are dispersed into TPI using ultrasonic vibrations. Particle size of nanocrystals is obtained from X-ray diffraction and found to be 1.84 nm. Thermo-mechanical properties (Tg and storage modulus) are measured by dynamic mechanical analyzer (DMA), while thermal conductivity is a measured using the transient plane source (TPS) technique. It is observed that glass transition temperature and thermal conductivity are higher while storage modulus and mechanical properties are lower for CdS-TPI nanocomposites than for pure TPI. This has been explained on the basis of structural changes occurring due to introduction of CdS as filler into the TPI.


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 951 ◽  
Author(s):  
Yujing Tang ◽  
Chao Tang ◽  
Dong Hu ◽  
Yingang Gui

In this paper, a molecular dynamics simulation method was used to study the thermo-mechanical properties of cross-linked epoxy resins doped with nano silica particles that were grafted with 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino)ethylamino]-propyl-trimethoxysilane with different chain lengths. Firstly, a set of pure epoxy resin models, and four sets of SiO2/EP composite models were established. Then, a reasonable structure was obtained through a series of optimizations using molecular dynamics calculations. Next, the mechanical properties, hydrogen bond statistics, glass transition temperature, free volume fraction, and chain spacing of the five models were studied comparatively. The results show that doped nano silica particles of surfaces grafted with 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino)ethylamino]-propyl-trimethoxysilane with different chain lengths enhanced mechanical properties such as elastic modulus, shear modulus, and volume modulus obviously. The glass transition temperature increased by 15–16 K, 40–41 K, and 24–27 K, respectively. Finally, the data show that the cross-linked epoxy resin modified by nanoparticles grafted with N-(2-aminoethyl)-3-aminopropyl trimethoxysilane had better effects for improving thermo-mechanical properties by the comparatively studying the five groups of parameter models under the same conditions.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 681-690
Author(s):  
Lei Guo ◽  
Shilin Ding ◽  
Shuai Yuan ◽  
Xiaofeng Gou ◽  
Fenglin Cai ◽  
...  

Abstract To study the effect of doping hexagonal boron nitride (h-BN) on the thermal properties and insulation resistance of epoxy resin (EP) and the mechanism of this effect, h-BN/epoxy composites with h-BN content of 0, 10, 20, 30, and 40 phr were prepared. Meanwhile, the corresponding molecular dynamics model of h-BN/epoxy composites was established, and the thermal conductivity, volume resistivity, glass transition temperature, and microstructure parameters of h-BN/epoxy composites were obtained. When the h-BN content is 40 phr, the thermal conductivity of h-BN/epoxy composite is increased by 138% compared to pure EP, and the glass transition temperature is increased by 76 K. At the same time, doping h-BN will reduce the insulation performance of EP. However, the lowest volume resistivity of h-BN/epoxy composite is still 1.43 × 1015 Ω·cm, and the EP composite still has good insulation performance. The fraction free volume and mean square displacement of EP decrease with the doping of h-BN, which indicates that h-BN can hinder the movement of molecular segments of EP, which is the reason for the increase in glass transition temperature.


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