Materials Science
Rana Mahdi Salih; Shanaz Husein Ahmad
Abstract
The current work focuses on assessing flexural properties, and water uptake of polymeric composites prepared using various reinforcements. These additives consist of kaolinite nano clays and rock wool (RW). In addition to a polymer blend that consists of epoxy and polyester resins as the matrix. The ...
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The current work focuses on assessing flexural properties, and water uptake of polymeric composites prepared using various reinforcements. These additives consist of kaolinite nano clays and rock wool (RW). In addition to a polymer blend that consists of epoxy and polyester resins as the matrix. The castings were made using a hand lay-up approach. Nanoclay (NC) was added in weight fractions of 5% and 7%, together with RW added in a volume fraction of 10% as reinforcement. The impact test was employed to decide the optimum mixing ratio of the polymer blend that used as a matrix. From the results the blend consisting of 80 wt.% epoxy and 20 wt.% polyester has the highest impact strength value. Thermal analysis was done using differential scanning calorimetry (DSC) as a characterization method to assess the miscibility of the polymer blend. The polyester/epoxy blend showed the maximum flexural strength, which determined as (57.4) MPa. While the hybrid reinforcement using NC (5 wt.%) and RW (10%) lowered the flexural strength to 16.53 MPa. From the water absorption test results showed that, in addition to the standard concentration, the type of material also affects water, in addition to the ratios of its components. Finally, DSC results revealed the presence of two different glass transition temperatures, which indicates that the epoxy/polyester blend is immiscible and there are two distinct phases in this matrix.
Materials Science
Hajer A. Ali; Nahida J. Hameed
Abstract
To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 ...
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To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 nanoparticles were tested using scanning electron microscopy (SEM). The mechanical properties (tensile strength and elongation) were improved at a fixed level of Cellulose Acetate+ 2% TiO2+1.5wt% ZnO loading. Beyond that level of loading, they decreased. The tensile strength was decreased due to some degrees of agglomeration of filler particles above a critical content. Fourier-Transform Infrared Spectroscopy (FTIR) was conducted to reveal the microstructures and chemical composition of as-prepared composite films. The wettability of the films was also determined by the sessile drop method. An increase in contact angle was also observed by the addition of ZnO content from 70.6° to 77.1° compared to pure Cellulose Acetate, which indicated a value of 61.3°. Antibacterial activity against Escherichia coli and Staphylococcus aureus was enhanced after incorporation of ZnO-TiO2 compared with pure CA. The enhanced wettability and antibacterial activity of the prepared films suggest that they could be used for packaging applications.
Materials Science
Sahar I. Ahmed; Aqeel S. Al-Adili; Awham M. Hameed
Abstract
Conventional concrete is recognized for its high density, which leads to a higher cost of building foundations and columns. Recently, many efforts have been made to produce lower density concrete with acceptable and applicable mechanical properties. One option can reduce the density of the conventional ...
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Conventional concrete is recognized for its high density, which leads to a higher cost of building foundations and columns. Recently, many efforts have been made to produce lower density concrete with acceptable and applicable mechanical properties. One option can reduce the density of the conventional concrete by using partial or total replacement of porcelanite instead of natural gravel. Porcelanite aggregate concrete can be prepared by adding different ratios of porcelanite and several other additives to the mortar, depending on the required density of the prepared porcelanite concrete. This study aims to assess porcelanite aggregate concrete components, manufacturing methods, and features of porcelanite aggregate concrete. Furthermore, this literature review aims to appraise and provide a complete vision of the testing program, including compressive strength, density, porosity, splitting tensile strength, and water absorption of porcelanite aggregate concrete. Also, this paper focuses on studying the development and applications of the porcelanite aggregate concrete, which will be presented in detail through this study.
Materials Science
Faten Hasan Gata; ENAS MHUI
Abstract
In this paper, Mortar was prepared from medium alumina refractory grog, bricks crashed as a mean material to a particular size, and Iraqi raw (kaolin or bentonite) as binding materials. Refractory bricks were crushed, milled, then sieved to three particle sizes: fine as (1.18 >fine> 0) mm, medium ...
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In this paper, Mortar was prepared from medium alumina refractory grog, bricks crashed as a mean material to a particular size, and Iraqi raw (kaolin or bentonite) as binding materials. Refractory bricks were crushed, milled, then sieved to three particle sizes: fine as (1.18 >fine> 0) mm, medium as (2.36 > medium > 1.18) mm, crushed as (400 > coarse > 2.36) mm. Then these particle sizes were mixed with Iraqi raw kaolin or bentonite with selected ratios (10,15,20,30 and 40) %. Specimens were formed by the wetting method, then drying it at laboratory temperature for one day, followed by firing it at 1200 ℃. Results showed that the porosity of specimens decreases when increasing the clay ratio from 3-4% (kaolin or bentonite), and the bond strength between grog and clay increases when increasing the clay ratio from 2-3% (kaolin or bentonite). Also, the diametrical strength increases when increasing the clay ratio from 4-7% (kaolin or bentonite). The thermal shock results showed that K-mortar is better than B-mortar, depending on the results we obtained through the effect of temperature and diametrical strength. The SEM results showed that mortar structure was produced by adding 40% bentonite with small irregularly shaped. The mortar was produced by adding 40% of kaolin which possesses regular mullite crystals. Finally, the results of the test EDS that K-mortar were revealed in showed that there is no adsorption of carbon while B-mortar showed that there is adsorption of carbon atoms.
