Epoxy/oil fly ash composites prepared throughin situpolymerization: Enhancement of thermal and mechanical properties

2014 ◽  
Vol 37 (2) ◽  
pp. 512-522 ◽  
Author(s):  
Shanmugam Nagendiran ◽  
Adel Badghaish ◽  
Ibnelwaleed A. Hussein ◽  
Abdelrahman Nasr Shuaib ◽  
Sarfaraz Ahmed Furquan ◽  
...  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Numan Salah ◽  
Abdulrahman Muhammad Alfawzan ◽  
Abdu Saeed ◽  
Ahmed Alshahrie ◽  
Waleed Allafi

AbstractCarbon nanotubes (CNTs) are widely investigated for preparing polymer nanocomposites, owing to their unique mechanical properties. However, dispersing CNTs uniformly in a polymer matrix and controlling their entanglement/agglomeration are still big technical challenges to be overcome. The costs of their raw materials and production are also still high. In this work, we propose the use of CNTs grown on oil fly ash to solve these issues. The CNTs of oil fly ash were evaluated as reinforcing materials for some common thermoplastics. High-density polyethylene (HDPE) was mainly reinforced with various weight fractions of CNTs. Xylene was used as a solvent to dissolve HDPE and to uniformly disperse the CNTs. Significantly enhanced mechanical properties of HDPE reinforced at a low weight fraction of these CNTs (1–2 wt.%), mainly the tensile strength, Young’s modulus, stiffness, and hardness, were observed. The tensile strength and Young’s modulus were enhanced by ~20 and 38%, respectively. Moreover, the nanoindentation results were found to be in support to these findings. Polycarbonate, polypropylene, and polystyrene were also preliminarily evaluated after reinforcement with 1 wt.% CNTs. The tensile strength and Young’s Modulus were increased after reinforcement with CNTs. These results demonstrate that the CNTs of the solid waste, oil fly ash, might serve as an appropriate reinforcing material for different thermoplastics polymers.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2919 ◽  
Author(s):  
Giuseppina Roviello ◽  
Laura Ricciotti ◽  
Antonio Jacopo Molino ◽  
Costantino Menna ◽  
Claudio Ferone ◽  
...  

This research investigates the preparation and characterization of new organic–inorganic geopolymeric foams obtained by simultaneously reacting coal fly ash and an alkali silicate solution with polysiloxane oligomers. Foaming was realized in situ using Si0 as a blowing agent. Samples with density ranging from 0.3 to 0.7 g/cm3 that show good mechanical properties (with compressive strength up to ≈5 MPa for a density of 0.7 g/cm3) along with thermal performances (λ = 0.145 ± 0.001 W/m·K for the foamed sample with density 0.330 g/cm3) comparable to commercial lightweight materials used in the field of thermal insulation were prepared. Since these foams were obtained by valorizing waste byproducts, they could be considered as low environmental impact materials and, hence, with promising perspectives towards the circular economy.


2014 ◽  
Vol 51 (5) ◽  
pp. 570-582 ◽  
Author(s):  
Joon Kyu Lee ◽  
Julie Q. Shang

Fly ash is often used as a binder for modifying the properties of geomaterials, such as organic and expansive soils, sludge from water treatment, dredged sediments, mine tailings, etc. Changes in thermal and mechanical properties of compacted mixtures of mine tailings and fly ash are studied over a curing period of 120 h. The study includes the measurement of thermal conductivity, temperature, unconfined compressive strength, and elastic modulus. Effects of the amount of fly ash added to mine tailings, molding water content, and compaction energy on these properties are investigated. Pore-size distribution and surface texture are analyzed to characterize the microstructures of fly ash treated–mine tailings. Relationships between the thermal conductivity and properties that capture packing and mechanical characteristics of mine tailings and fly ash mixtures are established. These observations provide enhanced understanding of thermal, mechanical, and structural properties of fly ash–treated mine tailings, which is associated with the hydration process at the early stage of the mixtures.


2012 ◽  
Vol 204-208 ◽  
pp. 4151-4155
Author(s):  
Zhan Bing Li ◽  
Xiu Wen Wu ◽  
Xiao Chao Chen

Expanded perlite insulation samples were prepared with expanded perlite as aggregate, aluminum dihydrogen phosphate as binder and fly ash as addition by mixing, molding, drying and calcination. The effects of fly ash mass percentage on the compressive strength, thermal conductivity, moisture content and density of the samples were studied. The results indicated that the combination properties of adding 10 % fly ash were the best among the all samples according to the national standards (GB/T10303-2001) No 350 Qualified of expanded perlite insulation products. Its compressive strength, thermal conductivity, moisture content and density were 0.456 Mpa, 0.08165 W/ (m K), 0.02 mass % and 259 kg/m3, respectively.


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