scholarly journals Barrier Corrosion Protection Properties of Metakaolin Clay-Kadilux Epoxy Coatings on Galvanized Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fantaye Tasew ◽  
Ganesh Thothadri

Epoxy polymer, an illustrious barrier corrosion protective coating, was reinforced with metakaolin clay, an eco-friendly inorganic filler to enhance the barrier corrosion protection properties in water and in acidic environment on galvanized steel plates. Various proportions 0, 1, 3, 5, and 7 wt.% of metakaolin fillers were mixed intrinsically with kadilux epoxy and characterized for thermal stability, water absorption according to ASTM G31, and acid immersion according to ASTM D-570 standards, respectively. The reinforced coatings minimized the pore size and density, lower water absorption, and better acid resistance properties especially at 7 wt.% of the fillers. The thermal stability of the films improved beyond 5 wt.% of filler composition.

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Iwona Zarzyka

The work focuses on research related to determination of application possibility of new, ecofriendly boroorganic polyols in rigid polyurethane foams production. Polyols were obtained from hydroxypropyl urea derivatives esterified with boric acid and propylene carbonate. The influence of esterification type on properties of polyols and next on polyurethane foams properties was determined. Nitrogen and boron impacts on the foams’ properties were discussed, for instance, on their physical, mechanical, and electric properties. Boron presence causes improvement of dimensional stability and thermal stability of polyurethane foams. They can be applied even at temperature 150°C. Unfortunately, introducing boron in polyurethanes foams affects deterioration of their water absorption, which increases as compared to the foams that do not contain boron. However, presence of both boron and nitrogen determines the decrease of the foams combustibility. Main impact on the decrease combustibility of the obtained foams has nitrogen presence, but in case of proper boron and nitrogen ratio their synergic activity on the combustibility decrease can be easily seen.


2019 ◽  
Vol 29 (3) ◽  
pp. 145
Author(s):  
Seenaa Ibrahim Hussein ◽  
Nadia Abbas Ali ◽  
Harith Ibrahim Jaafar ◽  
Zaniab Raheem Muslem

Sol-gel method is the simplest method and has to preparation of nano particles, nano fibers, and nano flaks. The preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (bending,and hardness), thermal properties. The effect of water absorption on bending and hardness test for tetraethylorthosilicate (TEOS) and epoxy hybrid have been investigated. TEOS with (0%,2%,4%,6%and 8%) volume per-centage mixed with epoxy to prepared sheets of hybrid, these sheets cut as samples for ASTM water absorption, bending and hardness tests. The results show that, adding TEOS to epoxy will increase absorbance of water. bending test shows that there are increase in values of bending stress with increasing TEOS but after im-mersion in water all the values for bending stress will reduce. Hardnessvalues at least for the samples immersion in water from dry samples, occur the diffusion of molecules water in the polymer and hybrids leads to space molecular chains for each other and decrease the hard-ness values. Thermal stability of hybrids increase with increasing TE


2017 ◽  
Vol 8 ◽  
pp. 1032-1042 ◽  
Author(s):  
Romana Cerc Korošec ◽  
Polona Umek ◽  
Alexandre Gloter ◽  
Jana Padežnik Gomilšek ◽  
Peter Bukovec

α-MnO2 nanorods were synthesized via the hydrothermal decomposition of KMnO4 in an acidic environment in the presence of Co2+ and Cr3+ ions. Reactions were carried out at three different temperatures: 90, 130 and 170 °C. All prepared samples exhibit a tetragonal MnO2 crystalline phase. SEM–EDS analysis shows that cobalt cations are incorporated to a higher degree into the MnO2 framework than chromium ions, and that the content of the dopant ions decreases with increasing reaction temperature. The oxidation of Co2+ to Co3+ during the reaction was proved by an XANES study, while EXAFS results confirm that both dopant ions substitute Mn4+ in the center of an octahedron. The K/Mn ratio in the doped samples synthesized at 170 °C is significantly lower than in the undoped samples. Analysis of an individual cobalt-doped α-MnO2 nanorod with HAADF-STEM reveals that the distribution of cobalt through the cross-section of the nanorod is uniform. The course of thermal decomposition of the doped nanorods is similar to that of the undoped ones. Dopant ions do not preserve the MnO2 phase at higher temperatures nor do they destabilize the cryptomelane structure.


2017 ◽  
Vol 757 ◽  
pp. 40-45 ◽  
Author(s):  
Sawitree Suckley ◽  
Piyanuch Deenuch ◽  
Natchaya Disjareon ◽  
Suttinun Phongtamrug

In this research work, natural fiber reinforced composites of bagasse fiber-epoxy resin were prepared. The chemical treatments using sodium hydroxide (NaOH) at 1,3,5,7 wt% were carried out to modify the fiber properties. Thermogravimetric analysis (TGA) was used to study the thermal stability of treated and untreated fibers. The effects of fiber treatment and fiber contents on mechanical properties of bagasse-epoxy composite were investigated. The characteristics of bagasse-epoxy resin composites exposed to high temperature as well as water absorption behavior were determined. The results from the TGA revealed that alkalization improved thermal stability of bagasse fiber. Treated bagasse fibers also had lower moisture content as compared to untreated fiber. The experimental results showed that the flexural properties of composites prepared from treated bagasse fibers were enhanced as compared to the untreated fiber composite. Thermal degradation study demonstrated that treated bagasse fiber composites experienced lower weight loss than untreated fiber composites. From water absorption study, it was observed that the treated bagasse fiber composites had lower water absorption values than those of untreated fiber based composites.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jin-Luen Phua ◽  
Pei-Leng Teh ◽  
Supri Abdul Ghani ◽  
Cheow-Keat Yeoh

Graphene nanoplatelets (GNP) filled epoxy composites ranged from 0.2 to 5 vol.% were prepared in this study using simple heat assisted bath sonication for better GNP dispersion and exfoliation. The effects of GNP filler loading via heat assisted bath sonication on the mechanical properties and thermal deformation behaviour were investigated. Improvements on flexural strength and fracture toughness up to 0.4 vol.% filler loading were recorded. Further addition of GNP filler loading shows a deteriorating behaviour on the mechanical properties on the composites. The bulk electrical conductivity of the epoxy composites is greatly improved with the addition of GNP filler loading up to 1 vol.%. The thermal expansion of epoxy composites is reduced with the addition of GNP; however poor thermal stability of the composites is observed.


Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 588
Author(s):  
Lijie Huang ◽  
Hanyu Zhao ◽  
Hao Xu ◽  
Shuxiang An ◽  
Chunying Li ◽  
...  

Biomass materials have become a research focus for humankind, due to the decreasing availability of fossil fuels and the increasing release of greenhouse gas. In this work, we prepared biodegradable composites with waste cassava residues and polybutylene succinate (PBS) by modifying cassava residues using 4,4’-methylene diisocyanate phenyl ester (MDI) and tested their properties. The effects of MDI modification on the structure, mechanical properties, water absorption, microstructure, and thermal stability of the composites were studied via Fourier transform infrared spectroscopy, contact angle measurement, mechanical property testing, water absorption analysis, scanning electron microscopy, and thermogravimetric analysis, respectively. The results showed that the tensile strength and flexural strength of the material increased by 72% and 20.89%, respectively, when the MDI-modified cassava residue content was 30%. When 10% MDI-modified cassava residues were added, the tensile strength increased by 19.46% from 16.96 MPa to 20.26 MPa, while the bending strength did not change significantly. The water contact angle of the MDI-treated cassava residues exceeded 100°, indicating excellent hydrophobicity. Thus, MDI modification can significantly improve the mechanical properties and thermal stability of the biocomposite. The composites were immersed in distilled water for 96 h. The water absorption of the cassava residues/PBS composite was 2.19%, while that of the MDI-modified cassava residues/PBS composite was 1.6%; hence, the water absorption of the MDI-modified cassava residues/PBS composite was reduced to 26.94%. This technology has wide application potential in packaging, construction, and allied fields.


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