Dispersion and Impact Strength of Epoxy Resin/Nano-Al2O3 Composites

2013 ◽  
Vol 761 ◽  
pp. 161-164 ◽  
Author(s):  
Nai Kui Gao ◽  
Zhou Xu ◽  
Chun Wu ◽  
Rui Hua Li ◽  
Hai Yun Jin

This paper focuses on the influence of nano-Al2O3 surface state and composite process on the dispersion of nano-Al2O3 filler. Toughening was performed to epoxy resin by nano-Al2O3, and the effect of impact property of epoxy resin/nano-Al2O3 composites was studied. The results showed that coupling agent treatment and high-speed shear dispersion can improve many properties of the composites. With nano-Al2O3 content increasing, the impact strength of the composites increased at first and then decreased. The maximum appears when the nano-Al2O3 content reached 3wt. %, no matter with or without the coupling agent treatment, which is 87.4% and 78.6% higher than that of monolithic epoxy resin respectively. The coupling agent treatment of nano-Al2O3 helped to improve the impact strength of the composites.

2011 ◽  
Vol 695 ◽  
pp. 465-468 ◽  
Author(s):  
Nai Kui Gao ◽  
Pu Dong ◽  
Xin Yu ◽  
Xin Fang ◽  
Chao Gao ◽  
...  

In this paper, composites with different contents of epoxy resin/nano-SiO2were fabricated, the influence of compounding process on nano-SiO2dispersion was studied, the microstructure and the relationship between impact strength and nano-SiO2content were investigated. The results showed that the distribution of nano-SiO2particles in the composites could be improved efficiently using high-speed shearing dispersion method. To composites with or without the coupling agent treatment, the impact strength grew with increasing nano-SiO2content, and increase to a maximum value when nano-SiO2content was 3wt.%. The maximum value was 75.4%, and 45.5% higher than that of monolithic epoxy resin respectively. With the nano-SiO2 content increased continually, the impact strength of composite materials decreased. The coupling agent treatment of nano-SiO2administered to improve the impact strength of the composites.


2016 ◽  
Vol 51 (9) ◽  
pp. 1197-1208 ◽  
Author(s):  
Wei Li ◽  
Hongyu Li ◽  
Xinguo Yang ◽  
Wei Feng ◽  
Hongyun Huang

This paper reported a facile one-pot strategy for fabrication of sulfonic graphene oxide–epoxy resin nanocomposites. The rheological and thermal properties were employed to characterize the viscosity and the curing temperature of epoxy resin. Fourier transform infrared spectra for sulfonic graphene oxide and nanocomposites indicated that the sulfonic graphene oxide contains chemical cross-linking responsible for better interactions with the epoxy resin. The state of dispersion was evaluated at different scales by still picture camera and scanning electron microscopy (SEM). Tensile property tests indicated that the tensile strength and elasticity modulus of sulfonic graphene oxide–epoxy resin nanocomposites decreased slowly with increasing of sulfonic graphene oxide content. The critical flexural property and impact strength of epoxy resin filled with sulfonic graphene oxide nanocomposites were measured. The content, size, and dispersion state of sulfonic graphene oxide were examined. It was found that the content of sulfonic graphene oxide has greater impact on both flexural property and impact strength of nanocomposites compared with other conditions. For instance, the impact strength increased by 113.0% and the flexural strength and modulus increased by 39.3% and 55.7% using 1 wt.% sulfonic graphene oxide as compared to neat epoxy resin.


2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.


2019 ◽  
Vol 960 ◽  
pp. 167-173
Author(s):  
Man Shi Qiu ◽  
Ze Hua Pan ◽  
Yuan Yuan Zhang ◽  
Yong Lan Li ◽  
Nai Kui Gao ◽  
...  

The surface state of aramid fiber was modified by coupling agent to characterize the change of the state. The fiber / epoxy resin composites were prepared to study the mechanical and electrical properties and the internal mechanism of how different surface states affect. The results show that, after the treatment with the coupling agent, the surface roughness of the aramid fiber is increased,and the content of Si on the surface reach 5.8%, thus the surface activity is enhanced. At the same time, the treatment makes the properties of composites further improved. When the filling amount of aramid fiber reaches 30 strands, the tensile strength increase by 38.4% due to the coupling agent. In the test of two-layer samples, the breakdown field strength of the composites before and after treatment with coupling agent increased by 15.9% and 20.2%, respectively.Key words: aramid fiber; coupling agent; surface state; mechanical properties; electrical properties


2014 ◽  
Vol 926-930 ◽  
pp. 198-201
Author(s):  
Li Ying Guo ◽  
Jin Lin Liu ◽  
Peng Cheng Huang ◽  
Jun Hai He ◽  
Shi Yang Bai ◽  
...  

Polyether imidazole ionic liquid (PIIL) was blended with general-purpose epoxy resin (EP). PIIL/EP was cured by ethylenediamine curing agent. The structure of PIIL/EP was determined by FTIR. The effect of the content of PIIL on the impact strength of EP was studied. The toughness of epoxy resin could be significantly improved by PIIL. The impact strength of the modified EP was improved with the increase of PIIL and leveled off when the content of PIIL was more than 45%, and the modified EP showed rubber elasticity obviously.


2013 ◽  
Vol 33 (2) ◽  
pp. 111-119
Author(s):  
Yiming Liu ◽  
Qing Liu ◽  
Bing Meng ◽  
Zhihua Wu

Abstract Polycaprolactone (PCL)-coated micro kaolin and nano-titania were prepared by high-speed hybrid mechanical coating. Poly(butylene succinate) (PBS)-coated inorganic particle composites were prepared by the melt-blending process. The influence of coated kaolin microparticles on the dynamic rheological behavior, non-isothermal crystallization behavior, micromorphology, and mechanical behavior were investigated. The effect of coated nano-titania on the mechanical properties of PBS-coated kaolin composites was also studied. A dynamic rheological property indicates that the complex viscosity of PBS-coated kaolin microcomposites is higher than neat PBS. Differential scanning calorimetry (DSC) implies that the micrometric size of kaolin particles restrains the crystallization of PBS. Scanning electronic microscopy (SEM) reveals a well dispersed state of coated kaolin in the polymer matrix. The impact strength of PBS-coated kaolin microcomposites is improved, while the tensile strength and elongation at break is decreased, but still appreciable. The introduction of coated nano-titania improves the impact strength dramatically, and the elongation at break of composites is considerable.


2010 ◽  
Vol 150-151 ◽  
pp. 698-702
Author(s):  
Zhi You Yang ◽  
Shao Rong Lu ◽  
Zhi Yi Huang ◽  
Chun He Yu ◽  
Kuo Liu

A new kind of lower-branched liquid crystalline polyester (LLCP) containing polyester mesogenic units was synthesized by p-hydroxybenzoic acid, terephthalyl chloride and trimellitic anhydride (TMA), then was used as collaborative modifier for the epoxy resin (E-51) with γ-azyl polyhedral oligomeric silsesquioxane (POSS). The experimental results showed that the LLCP / POSS could act as an effective toughening modifier for the epoxy resin. The impact strength of the composites modified with LLCP and POSS was 1.1 times higher than that of the unmodified system. The temperature of starting decomposition and maximum decomposition rate improved about 20 oC and 13 oC , respectively.


2021 ◽  
Author(s):  
Chenglin Zhang ◽  
Guohua Gu ◽  
Shuhua Dong ◽  
Zhitao Lin ◽  
Chuncheng Wei ◽  
...  

Abstract In this study, the nonisothermal differential scanning calorimetry (DSC) was carried out to evaluate the curing reaction of fiber/epoxy laminates. The optimal curing process of the prepreg was obtained by T-β extrapolation method and nth-order reaction curing kinetic equation. The bending strength, impact strength and thermodynamic properties of the composite laminates with different ply orientations were investigated, respectively. The results show that the apparent activation energy and the reaction order of the prepregs are 82.89 kJ/mol and 0.92, respectively. The curing process of carbon fiber/epoxy resin prepreg is 130 ℃ /60min + 160 ℃/30 min. The bending strength of [0]10 laminate is 1948.3 MPa, which is 11.8 times higher than that of [+ 45/-45]5s laminate, and 96.4% higher than that of [0/90]5s laminate. The impact strength of [0]10 laminate is higher than that of [+ 45/-45]5s and [0/90]5s laminates. The glass transition temperature (Tg) of the laminates is 142 ~ 146 ℃, and the loss factor of [0]10 laminate is significantly higher than that of [+ 45/-45]5s and [0/90]5s laminates. This research provides a theoretical basis for the further application of prepregs to fiber composite materials.


2020 ◽  
Vol 992 ◽  
pp. 285-289
Author(s):  
S.V. Vasiliev ◽  
Y.Y. Fedorov ◽  
A.V. Savvina

This article discusses effect of filler concentration on impact strength of an epoxy resin composite. The optimal ratio of resin and hardener is defined. Research of the effect of the concentration of the filler - carbon black P505 on the impact strength of a composite material based on epoxy resin ED-20 is made. According to the results of the study, it is shown that with an increase of concentration of the filler from P505 carbon black, the toughness decreases. Fractographic studies of the fracture surfaces of composites were also carried out, which indicate that the introduction of a filler leads to a decrease in the surface energy of destruction. Thus, studies of epoxy composite modified with technical carbon grade P505 showed a decrease in impact strength up to 4 times, depending on the increase in the mass fraction of the filler.


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