Influence of the Type of Epoxy Resin and Concentration of Glycidylisobutyl-POSS in the Properties of Nanocomposites

2017 ◽  
Vol 25 (8) ◽  
pp. 593-602 ◽  
Author(s):  
Marielen Longhi ◽  
Lucas Pandolphi Zini ◽  
Sandra Raquel Kunst ◽  
Ademir José Zattera

Epoxy resin is one of the most used resins for obtaining composites and coatings. Its properties have been modified using many materials, mainly based on nanotechnology, such as clays and polyhedral oligomeric silsesquioxanes (POSS). POSS may increase thermal and mechanical resistance and hydrophobicity of the epoxy resin. This study aims at characterizing epoxy nanocomposites, using two distinct resins (DGEBA and DGEBF) and an addition of glycidylisobutyl-POSS in contents of 2.5% and 5% (w/w), through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Samples showed an amorphous halo due to the epoxy resin and a characteristic peak of POSS. TGA results showed a greater residual mass in DGEBF systems due to its wider formation of crosslinks. FTIR spectra demonstrated a higher amplitude of the hydroxyl band in DGEBF 5% system, which may affect its hydrophilic behavior because of the molecular mobility and resin weight reduction. DMA results showed that DGEBA systems are more flexible than DGEBF.

2017 ◽  
Vol 899 ◽  
pp. 278-282 ◽  
Author(s):  
Marielen Longhi ◽  
Vinicius Pistor ◽  
Lucas Pandolphi Zini ◽  
Sandra Raquel Kunst ◽  
Ademir José Zattera

The present study aimed to characterize the structure of nanocomposites obtained from the incorporation of three different polyhedral oligomeric silsesquioxane (POSS) in an epoxy resin. glycidylisobutyl-POSS, triglycidylisobutyl-POSS and glycidyl-POSS were added (5% by weight) in an epoxy matrix, diglycidyl ether of bisphenol-A (DGEBA), through a sonication process. The nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and dynamic mechanical analysis (DMA). The XRD analysis presented a characteristic peak of POSS. The incorporation of glycidylisobutyl-POSS showed a significant increase in the value of glass transition temperature (Tg), being also the most effective in terms of dispersion. It should also be noted that glycidyl-POSS presented a greater influence on the thermal stability.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Dalia M. T. Mustafa ◽  
Sarkawt Rostam ◽  
Shujahadeen B. Aziz

In the present work, epoxy resin-based nanocomposites (NCPs) were fabricated with improved mechanical properties. The epoxy resin (EPR) was mixed with differing amounts of calcium titanate (CaTiO3) nanoparticles (NPs) and glass fiber. The results showed that the ternary system contained glass fiber exhibits low mechanical performance compared to binary [EPR:CaTiO3] system. The effect of fiber glass and NPs on the epoxy resin mechanical behavior was determined by conducting a tensile test for various specimen sets. From the mechanical characterizations, it was seen that there is a monotonic relationship between the NPs concentration and Young’s modulus. Additionally, NCPs samples were brittle in nature and the strain rate significantly decreased upon the addition of CaTiO3 concentration; while the tensile strength was increased. From the X-ray diffraction evaluation, it can be concluded that the addition of NPs have a great impact on the epoxy structure. Besides, the morphology appearance was in good agreement with structural and mechanical analysis.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.


2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.


1988 ◽  
Vol 41 (2) ◽  
pp. 323 ◽  
Author(s):  
JC Taylor ◽  
SR Pecover

It is shown that quantitative analysis of zeolite phases in mineral mixtures can be performed using calculated whole-pattern X-ray diffraction profiles and Bragg-Brentano patterns. The method was tested on binary and ternary standard mixtures containing quartz, heulandite, chabazite and stellerite, and gave zeolite weight percentages correct to within a few per cent. Structure analyses of the zeolites were necessary to obtain good calculated profiles. The platy zeolites heulimdite and stellerite had severe preferred orientation problems, which were minimised experimentally by adding Al powder diluent and an epoxy resin, and regrinding. Analyses of field samples are also described.


2010 ◽  
Vol 123-125 ◽  
pp. 247-250
Author(s):  
Yu Qing Zhang ◽  
Yu Xin He ◽  
Li Zhang ◽  
Jun Xian Li

A new type of EVA-g-PU/OMMT nanocomposites was synthesized through the method of chemical modification and melt intercalation. FTIR testing showed that the PU prepolymer was grafted on EVA main chains successfully. The structures of EVA-g-PU/OMMT nanocomposites were characterized by X-ray diffraction (XRD) and by high-resolution transmission electron microscopy (HRTEM). The enhanced storage modulus of EVA-g-PU/OMMT nanocomposites was characterized by dynamic mechanical analysis (DMA). The thermal stabilities of EVA/clay nanocomposites were also studied by thermal gravimetric analysis (TGA). Mechanical testing showed that the tensile strength and tear strength of EVA-g-PU/OMMT nanocomposites were far superior to pure EVA.


2004 ◽  
Vol 03 (04n05) ◽  
pp. 663-669 ◽  
Author(s):  
S.-J. PARK ◽  
F.-L. JIN ◽  
J.-R. LEE

A novel nanocomposites of modified clay in a glassy epoxy were prepared using a direct melt intercalation technique. The contents of oganoclay were varied with 0, 1, 2, and 3 wt% and N-benzylpyrazinium hexafluoroantimonate (BPH) was used for curing of epoxy matrix as a cationic latent catalyst. Dynamic mechanical analysis (DMA) measurement was performed to examine the glass transition temperature of the nanocomposites. As a result, X-ray diffraction indicated the intercalation of the epoxy chains happening inside the gallery of clay. The nanocomposites showed a higher glass transition temperature and storage modulus than those of the pristine epoxy. The mechanical interfacial properties of the nanocomposites were also investigated and the improvement in tearing energy of 160% over pristine epoxy was obtained.


Author(s):  
Tascila Saranti ◽  
Pamela Melo ◽  
Miguel Cerqueira ◽  
Fauze Aouada ◽  
Marcia Moura

The concern about consuming eco-friendly products has motivated research in the development of new materials. Therefore, films based on natural polymers have been used to replace traditional polymers. This study consists of a production of films based on gelatin reinforced with black pepper essential oil-loaded nanoemulsions and Cloisite Na+. The films were characterized by water vapor permeability, mechanical and thermal properties, surface contact angle, X-ray diffraction and scanning electron microscopy. It was observed that the films containing the nanoemulsion have higher permeability values and an increase in their mechanical resistance. The addition of nanoclay contributed to an increase in the surface hydrophobicity of the film and an increase in the tensile strength at break by about 150%. The addition of essential oil nanoemulsions led to an increase in thermal stability. The presence of clay dispersion contributed to the formation of a surface that was slightly rougher and grainier. The addition of the black pepper essential oil nanoemulsion resulted in an increase in porosity of the gelatin matrix. Through X-ray diffraction analysis, it was possible to conclude that both the polymeric gelatin matrix and the essential oils nanoemulsion are intercalated with the clay dispersion.


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