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vulcanization
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An Investigation on the Role of Metal-Organic Framework (MOF) on the Network Structure and Physical/Mechanical Properties of EPDM Rubber
, M.Sc. Thesis Sharif University of Technology ; Molvai, Hossein (Supervisor)
Abstract
Ethylene-propylene-diene monomer rubber (EPDM) is one of the elastomers that shows non-polar behavior, high elasticity at low temperatures, excellent thermal and ozone resistance, and high electrical resistance. In this respect, it is used in various applications such as sealing materials, conveyor belts, waterproof materials, cables, etc. One of the most important applications of this rubber is its use as a sealing material. In this case, the resilience behavior plays an important role in the sealing behavior of the EPDM rubber. Especially in cases such as the car's hydraulic braking system where high service temperatures and dynamic stresses are applied, resilience behavior will be more...
Studying the Effect of Dynamic Vulcanization of EPDM on Scratch Resistance of Rubber-Modified Polypropylene
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor)
Abstract
Polypropylene is a commodity thermoplastic with good physical and mechanical properties along with fair recyclability and cost. However, the application of polypropylene is limited in some cases, especially in automotive industry, as a result of inappropriate toughness of this material. Although rubber toughening of polypropylene is a method used to increase the toughness, it reduces scratch resistance. Studies performed in the polymer group of this department reveal that the cavitation resistance of elastomeric phase and its bonding to the matrix are two effective parameters in scratch resistance of this material. In this study, it is tried to alter the cavitation resistance of elastomeric...
The Role of Surface Functionalization of Nanodiamond on the Vulcanization Kinetics and Network Structure of SBR
, M.Sc. Thesis Sharif University of Technology ; Shojaie, Akbar (Supervisor)
Abstract
Elastomers are flexible polymers with various uses in different industries. But this materials dont havevalid usages without correct fillers. Today Nano technology has a main role in the industry. one of the important reasons is rubber quality improvement with adding just a little amount of this clays, opposite to Carbon Black. To achieve a high quality polymer composite, it is necessary to learn about physical and mechanical properties of nano clays and the interaction between Nano clays and matrix. Because of the effect of nano clays on vulcanization, this issue is noticeable . Nano diamond is a nanoclay used to improve rubber quality. But this method is new because of the complicated...
Dimensional accuracy analysis of wax patterns created by RTV silicone rubber molding using the Taguchi approach
, Article Rapid Prototyping Journal ; Volume 13, Issue 2 , 2007 , Pages 115-122 ; 13552546 (ISSN) ; Akbari, J ; Barati, E ; Sharif University of Technology
2007
Abstract
Purpose - Dimensional accuracy analysis of wax model created by room temperature vulcanization (RTV) silicone rubber molding to be used in investment casting is presented. The purpose of this paper is to discuss the effective parameters of dimensional accuracy in RTV tooling technique. Design/methodology/approach - After producing a pattern by stereolithography (SLA) and then creating the RTV silicone rubber mold by the SLA pattern, dimensional accuracy of wax models produced by RTV tool are analyzed. Design of experiments (DOE) using the Taguchi approach is used for analysis and determination of optimum condition. Findings - Experiments show that the dimensional accuracy in RTV technique is...
Vulcanization kinetics and reversion behavior of natural rubber/styrene-butadiene rubber blend filled with nanodiamond - The role of sulfur curing system
, Article European Polymer Journal ; Volume 81 , 2016 , Pages 98-113 ; 00143057 (ISSN) ; Shojaei, A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
The effect of nanodiamond (ND) particles on the network structure and vulcanization kinetics of natural rubber (NR)/styrene-butadiene rubber (SBR) blend vulcanized by three different curing systems, namely conventional (CV), semi-efficient (SEV) and efficient (EV), was investigated. The filler dispersion, crosslink density, curing kinetics and reversion behavior were fully studied. The state of ND dispersion in the rubber matrix was investigated by the field emission scanning electron microscope (FESEM). Swelling experiments and tensile tests exhibited that upon incorporation of ND crosslink density of NR/SBR blend was enhanced significantly due to the large surface area of nano filler...
Comprehensive Study of an Ag@Pt Core–shell Nanoparticles Supported on Carbon Structure in a Proton Exchange Membrane Fuel Cell
, Ph.D. Dissertation Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Bastani, Dariush (Supervisor)
Abstract
Core-shell structures of Ag@Pt nanoparticles (NPs) dispersed on Carbon Vulcan XC-72, Multiwalled carbon nanotube and reduced graphene oxide (rGO) support containing different Ag:Pt mass ratios and applied to the oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC) were synthesized by the ultrasonic and reduction treatment method. The morphology of as-prepared catalysts characterized by the high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and induced coupled plasma atomic emission spectroscopy (ICP-OES). The ORR activities and stabilities of catalysts were studied through electrochemical measurements utilizing the Cyclic Voltammetry...
Degradation of azo dye methyl red by saccharomyces cerevisiae ATCC 9763
, Article International Biodeterioration and Biodegradation ; Volume 125 , 2017 , Pages 62-72 ; 09648305 (ISSN) ; Bagheri Lotfabad, T ; Heidarinasab, A ; Yaghmaei, S
Abstract
Azo dyes are common dye groups widely used in different industries. Industrial effluents which contain these dyes pervade water resources and have various known and unknown physiological effects on living organisms. In this study, methyl red (MR) was proposed as a model azo dye to examine the capability of Saccharomyces cerevisiae ATCC 9763 for cleavage of the azo bond leading to decolourization. The spectrophotometry method showed that complete decolourization occurred statically during ≃12 h and this time reduced to several minutes less than 10 min where cell mass increased. Thin layer chromatography (TLC), mass spectroscopy and Fourier transform infrared (FTIR) confirmed degradation of...
Sequential RTV/(TiO2/SiO2) nanocomposite deposition for suppressing the leakage current in silicone rubber insulators
, Article Applied Physics A: Materials Science and Processing ; Volume 126, Issue 5 , 2020 ; Mohammadi, M ; Shayegani Akmal, A. A ; Samadpour, M ; dehghani, M ; Parvazian, E ; Sharif University of Technology
Springer
2020
Abstract
The sequential deposition method is introduced for suppressing the leakage current in silicone rubber insulators. Room temperature vulcanizing silicone and TiO2/silica nanocomposites are sequentially deposited on silicone insulators surface. TEM results showed that TiO2 nanoparticles size is about 20–30 nm, and the structural study revealed their anatase crystalline structure. Silica nanoparticles are deposited on the surface of insulators by spray deposition. The contact angle was enhanced from 104° to 149° after nanoparticles deposition, which confirms the hydrophobicity improvement. Results show that leakage current for nanocomposite samples in a contaminated environment reduced to about...
Water repellent room temperature vulcanized silicone for enhancing the long-term stability of perovskite solar cells
, Article Solar Energy ; Volume 218 , 2021 , Pages 28-34 ; 0038092X (ISSN) ; Heydari, M ; Mohammadi, M ; Parand, P ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
A key direction toward enhancing the long term and outdoor stability of the perovskite solar cells is encapsulation. As a result, a suitable encapsulation package is required to prevent moisture and oxygen penetration toward the perovskite solar cells. In this work, a low-cost commercially available bilayer structure of poly (methyl methacrylate)/ room-temperature vulcanizing silicone rubber (RTV) encapsulation package for enhancing the long term stability of the perovskite solar cells has been investigated. Encapsulated cells retained more than 80% of the initial efficiency at the environmental condition of 50% moisture, and room temperature after 1000 h, however reference cell efficiency...