فرشته مطیعی

In this study, graphene oxide is functionalized with benzidine and zinc oxide nanoparticles to improve adhesion and corrosion resistance properties. Nanoparticles were dispersed in an epoxy-based coating and applied as a coating on steel panels. The corrosion resistance of nano composite coatings was evaluated by salt spray test during 45 days of exposure. The results showed that the anti-corrosion performance of the coating containing 0.01% graphene oxide containing amine-zinc oxide with a penetration depth of 1.2 mm from scratch showed the highest corrosion resistance. The results of the salt spray and EIS tests show that with the increase of nanoparticles up to 0.01%, the anti-corrosion properties increased.

Since reusing of reclaimed tire is considered as part of a polymer matrix alternative, in this paper the WRP up to20 phr replaced with the BR / SBR elastomer compound and aged from240 to 960 hours under environmental conditions (23 ± 3 °c) in aging chamber. The effect of the WRP was investigated on their rheological and physico-mechanical properties. Composite morphology and structural analysis, as well as their thermal behavior, were followed by scanning electron microscopy (SEM) and thermal analysis (TG / DTG). The results show that the presence of waste rubber powder up to20 phr as a substitute for the primary polymer matrix improves curing rate, steress crack resistance, tensile strength and hardness of the compound. The performance of BR / SBR / WRP composites compared to the BR / SBR samples shows a slight change in the mechanical properties, while modulus and composite hardness are associated with a slight increase. The use of waste rubber powder, as well as its cost-effectiveness, helps to protect the environment, reduce chemical consumption, prevent water and soil pollution, and reduce landfill, etc.

In this research, TiO2-Zr nano-photocatalyst was firstly developed with the aim of improving the photocatalytic activity of titanium dioxide via sol-gel method. The recovery of catalysts in acidic, alkaline and thermal conditions was also studied.

This research was done on a laboratory scale. The structures and properties were recognized with (BET), (FT-IR), (FE-SEM), and (XRD) methods and the band gap value of the synthesized nano photocatalyst found to 3 eV with DRS. Also, the effect of color concentration, soluble pH, catalyst powder concentration and contact time was kept constant in order to economically effect on the efficacy of dyeing. Then, photocatalytic activity was evaluated for degradation of organic pollution days Acid yellow 36 in aqueous solution specimen by the UV-Vis spectrophotometer and total organic carbon (TOC).

Finally, after obtaining the optimum conditions for degradation efficiency, it was compared with titanium dioxide photocatalyst, which revealed that increase in efficiency due to changes in the band gap and, as a final point, shows the power of photocatalytic activity of synthetic doped material in degradation organic environmental pollutants.

It founded that doping Zr ions to the TiO2 lattice causes decreasing band gap value, so As a result, the necessary energy to stimulate the electrons from the valence band reduced in results wavelength shift up. The photocatalytic activity has a significant impact on color reduction and has a high potential for the decolorization organic dye wastewater.

In this paper, CuO - ZnO nanocomposite was synthesized and its photocatalytic dye degradation ability from colored wastewater was studied. Basic Red 18 (BR18) and Basic Violet 16 (BV16) were used as model dyes. The characteristics of CuO - ZnO of were inves tigated using Fourier transfo rm infrared (FT - IR) spectroscopy , scanning electron microscope (SEM) and X - ray diffraction (XRD). Photocatalytic dye degradation by CuO - ZnO was studied by UV - Vis spectrophotometer. The effects of CuO - ZnO dosage, initial dye con centration and salt on dye degradation were evaluated. The results indicated that CuO - ZnO as a photocatalyst could be used to degrade dyes from wastewa ter. Prog. Color Colorants Coat.

Due to the gel formation in polybutadiene and some of the problems raised in rubber industry such as groove cracking in products، quantification of the gel content and identification of the microstructure of butadiene elastomer is extremely important. In this paper، the gel content in polybutadiene rubber was identified by differential scanning calorimetry. The thermal decomposition of the polybutadiene rubber was studied by thermal analysis methods in 0-650°C. The thermal decomposition، in the same temperature range، of the polymer with different gel contents under the similar conditions showed that the oxidation and decomposition of the samples occur in three steps. The thermal analysis curves showed that the cis-trans isomerization occurs by increases in the gel content at lower temperatures of a wider thermal range with rising trans isomer and decreases in cis isomer contents، respectively. Also، with the increase in the gel content there is a tendency in lowering double bond density and there is higher energy release in oxidation and decomposition regions due to the breakage in crosslink density of polymer networks. According to the values resulting from enthalpy and heat flow rate، the thermal index was obtained for samples at two maximum temperatures related to two processes of cis-trans isomerization and the cyclization reaction. The gel content (C-C crosslinked) in polybutadiene rubber is determined by the interconnection between the ratio of heat flow index and gel content from the differential scanning calorimetry curves.

The Gel Content in Initial Poly Butadiene Reduces the Chemical Bonding and Adhesion During the Production And Curing Process And Causes the Groove Cracking.therefore in This Study, The Thermal Decomposition of the Polymer PBR was Studied by Methods STA In 0-650 ° C. Thermal Behavior of Poly Butadiene Different Samples Were Studied and Analyzed. DSC Curves Showed A Network Building. Physico Mechanical Properties of Rubber Compounds Based on BR Were Measured. The Results Showed that There is A Good Correlation Between Physicco-Mechanical and Groove Cracking of Tire Tread With The Percentages of Gel Content of Different Type of Initial PBR.

In this study four relevant factors, temperature, time, humidity and storage atmosphere were selected and the effect of each factor on aging of unvulcanized NR compound were studied at three different levels, based on measuring the ozone resistant and fatigue life time of rubber blends to monitor the extent of degradation. The optimal combination of mentioned factors was determined based on Taguchi protocol, and maximum fatigue life was obtained. Taguchi experimental design reduces cost and improves quality. The result of this work can be useful for rubber industries who storage their final compounds more than one day in the production lines.