احمد نعلبندی

In this paper, anionic emulsifiers of disodium lauryl ether sulfosuccinate and sodium lauryl ether sulfosuccinate ethoxylated were synthesized in laboratory scale. These chemicals were used in preparation of diesel/saline water and diesel/tap water emulsions, and the stability of the emulsions were examined with a procedure adopted by National Iranian South oil Company. Accordingly, by addition of one mililitre of water solutions containing 25,37 and 50 weight percent of the emulsifiers (synthesized chemical) to 100 mililiter mixtures of diesel/saline water and diesel/tap water having volume ratios of 60/40 and 70/30, and then homogenizing the mixtures with homogenizer working at high speed, a series of emulsions were prepared. By examining the stability of the emulsions at room temperature (for 24 hrs) and °90C (for 4 hrs), the performance of the synthesized chemicals as emulsifier in preparation of water-based emulsion drilling fluids were evaluated. The results of these experiments confirmed that the chemicals, in comparison with a commercial sample, had acceptable performance, because sodium lauryl ether sulfosuccinate ethoxylated in formulation of diesel/saline water and diesel/tap water, and also disodium lauryl ether sulfosuccinate in emulsions of diesel/ saline water showed being stable emulsifiers. In order to study the environmental effects of the synthesized chemicals, their aerobic biodegradation processes were examined by measuring the amount of carbon formed in their water solutions against incubation time, in comparison with a control sample. The results of the experiments showed that the two chemicals can be safely used as biodegradable emulsifiers in formulations of water based emulsion drilling fluids.

This paper demonstrates the successful use of nanoclay in a model truck tire formulation and reports the comparison of mechanical and dynamic mechanical properties for a number of natural rubber composites based on carbon black and organoclay. We find that stearic acid modified organoclay seems to dominate reinforcing capabilities as compared with unmodified organoclay. It is also found that the model truck tire compounds can be formulated with 40% less fossil fuel resources without sacrificing various properties. It is also shown that the truck tire formulation made with hybrid fillers offers better rolling resistance performance as compared with a conventional standard compound.

The solubility parameter of a group of methyl esters of fatty acids, the main components of biodiesel, was calculated using the group incremental method proposed by Van Krevelen. The solubility parameter of biodiesel was compared with that of a series of rubbers like EPDM, butyl rubber, polyisoprene, polybutadiene, SBR (with different content of styrene) and nitrile rubber (with different content of acrylonitrile) and it was shown that biodiesel is an effective solvent for all the above rubbers, except nitrile rubber. The solubility experiments being carried out manifest Polyisoprene; Polybutadiene and SBR are easily soluble in biodiesel, while Polystyrene is not, gives a cloudy solution. Considering on the solubility parameter of biodiesel and those of the above rubbers, it was concluded that biodiesel is able to behave as an internal lubricant in the matrix of diene rubbers. The same situation occurs with the common aromatic mineral oil plasticizer known as T-RAE. The experimental evaluation of biodiesel used as plasticizer in an SBR based rubber compound have led to the conclusion that biodiesel is reactive with the sulphur curing agents,subtracting Sulphur to the crosslinking Polymer chains and leading to vulcanizate with lower moduli, tensile and hardness and higher elongation in comparison to reference compound fully plasticized with an aromatic mineral oil. Moreover, it is expected that biodiesel to be a good low temperature plasticizer because the low elastic modulus observed is desired in a winter tire tread for a good grip on snow and ice. The present work is only an exploratory work, and the tire tread formulation with biodiesel was not optimized.

In situ epoxidation reaction of soybean oil from the raw materials of acetic acid and hydrogen peroxide was performed for the first time in the presence of a heterogeneous catalyst، namely silica sulfuric acid within the temperature of 30-75 °C. By altering the molar ratios of soybean oil، acetic acid and hydrogen peroxide and also the reaction temperature and percent of catalyst، the optimum condition of the epoxidation reaction for obtaining the highest value of epoxy percent in epoxidized soybean oil was achieved. The maximum oxirane value obtained in he product was 6% which was achieved at the optimum condition of the reaction، involving the molar ratio of soybean oil، acetic acid and hydrogen peroxide of 1:0. 5:1. 1 respectively، at the temperature of 60 °C and in the presence of 5% catalyst. Moreover، in comparison with the other acid liquid catalysts usually used for epoxidation reactions، silica sulfuric acid have several advantages including ease of usage، being inexpensive، having high chemical activity and safety and being environmentally friendly.

In this study، a rubber gasket with the dimensions of 1500 mm × 500 mm was fabricated using a reverse engineering method and utilizing a special rubber gasket as a reference. In order to identify the components in the reference gasket، some analyzing techniques such as pyrolysis، solvent extraction، and thermogravimetry as well as several analytical instruments including FTIR، EDAX، and XRD were used. In addition، some thermal characterizing instruments such as DSC and TGA were utilized to characterize the reference gasket and those fabricated herein. After assuring that the properties of the reference gasket were almost the same as rubber plates produced in laboratory، a number of rubber gaskets were produced using an industrial mold. To evaluate the quality of the fabricated gaskets and compare their properties with the reference gasket، some of the fabricated gaskets together with the reference gasket were placed inside an industrial amine heat exchanger for 35 days. The gaskets were then removed from the heat exchanger and tested for tensile strength، elongation at break، and hardness. This investigation showed that the rubber gaskets made according to the two rubber formulations in this work possessed almost the same properties as the reference gasket.

In this research a new eco-friendly nanocomposite material has been synthesized from natural rubber and magnetite nanoparticles. The poor oil resistance of natural rubber in the nanocomposites is exploited for the absorption of oil spills in sea. For this purpose, partially epoxidized natural rubber (ENR)/magnetite nanoparticle (MN) nanocomposites are prepared and the amount of crude oil absorption by them is studied. The extent of epoxidation is controlled in such a manner that the NR does not lose its elasticity while retaining to a significant degree its oil absorbing property. Epoxidation also serves as a means for binding sufficient quantity of MNs so that the composite can be recovered using a magnetic field. ENR with 5 mol% of epoxidation served as the best oil absorbent among all the absorbents studied as it was stable in crude oil even after many days of immersion. It is observed that each gram of ENR-MN nanocomposite absorbs 7 g of crude oil without any mass loss. The material was reused for several cycles without much loss in the capacity. The crude oil uptake of ENR-MN is greater than that of butyl rubber which is the most commercially used rubber for oil removal. Porous rubber was also synthesized for the first time as oil uptake is facilitated not only by the hydrophobicity but also by the capillary absorption. Porous ENR absorbed a relatively larger amount of oil and exhibited the highest stability. All the sorbents studied in this work have quite high absorption capacities to be applied practically with a very low water uptake and a few of the absorbents could be satisfactorily reused.

In this research, natural rubber was concurrent mixed with their formulation components and different amounts of polyethylene powder two-rolls mill. The resulting blends were then converted to cured composite films by compression molding at 150 degree centigrade. There are some evidences showing during rubber curing process, polyethylene was separated from rubber and migrated to the surface where it forms a thin film on the composite. Surface morphology of composite films were investigated by scanning electron microscope and it was found that after exposure to ozone, lamellae crystals were formed and grown within polyethylene on the surface. In addition, the effects of polyethylene on cross linking process during rubber curing were investigated using XANES spectroscopy which identifies sulfur structures in polymeric materials.

In this research, Nanoemulsions of water droplets in gas oil have been prepared using combination of nonionic surfactants. Three formulations of the emulsion containing various amount of water as 5, 10 and 14 volume fractions (based on 100 volume fractions of gas oil) have been prepared, clear and stable, using a mixture of two surfactants containing sorbitan monooleate (20%) and sorbitan trioleate polyoxyethylene (20 mole ethoxylated) (80%) and adjusting the system HLB at 10. The effect of water content on droplets size, fuel calorific value, amount of gas emissions (environmental pollutants) and the exhaust gas temperature have been studied in a diesel engine, and it has been found that the amount of nitrogen oxide, soot, particulates, unburnt hydrocarbons and carbon monoxide are reduced. This study shows that the average droplet size of water formed (being 19.3-39 nanometers in this research) depends on the total concentration of surfactants and the amount of water used.

Around the world, people are suffering the continuous increase in hydrocarbon fuel prices and are astonishingly following the fuel crisis. Due to this matter, there are initiatives to replace diesel fuel and gasoline with new alternatives which their resources are renewable and environmentally friendly. Daily increase in fuel consumption and the adoption of stringent emission norms, are motivated some researchers to find new alternative fuels for internal combustion engine. Many substituted fuels like Alcohol, Biodiesel, LPG, CNG have been already commercialized in the transport sector. Recently, the oil from pyrolysis of scrap tires has been interested to some engineers as fuel oil. With respect to production of 1.5 billions of scrap tires worldwide, and the fact that 50- percent of them are not possible to be properly recycled, and are inevitably accumulated in the environment have been forced researches to find alternative fuels from scrap tires. Following the inventions of tire pyrolysis processes under vacuum and also flow of nitrogen gas and production of tire pyrolysis oil (TPO), some initiatives for its utilization as fuel for diesel engine has been commenced. First, a researcher in 2008 used TPO as fuel in an internal combustion engine. He tried to compare the motor performance and its exhaust gases with those a common diesel engine. Then, another researcher in 2011 was blended TPO with different percentage of diesel fuel and used the mixtures as fuel for a diesel motor. He also investigated the motor performance and its exhaust emissions in the way as previous researcher. As the amount of polluting emissions for the mixtures of TPO and different percentage of diesel fuel are higher than those for pure diesel fuel, so we have endeavored to investigate the effect of adding ethanol to the mixture of TPO plus diesel fuel. Therefore, 10%, 15% and 20% of TPO were blended with diesel fuel and the mixtures were used as fuel in a single cylinder diesel motor. At the same time, the performance of motor and its exhaust emissions were analyzed. Then, with addition of 5%, 10% and 15% ethanol to the above fuel mixtures of TPO and diesel fuel, the same investigation and analysis have been carried out on motor and its emissions. The results show addition of ethanol to the blended mixture of TPO and diesel fuel lead to better burning of the mixture reducing its carbon monoxide (CO) and unburnt hydrocarbons (HC).

Recycled polypropylene (PP) fiber,waste tire powder have been used to remove spilled oil. The ASTM F726-99 method has been used to evaluate oil absorbing capability of PP fiber,it has been found that the fiber has a large rapid oil absorption capacity. The oil adsorption capacity of the fiber was dramatically reduced after a limited number of uses because of its poor elasticity. Tire powder which absorbs less oil more slowly,is more elastic than PP fiber,is capable to be used up to 100 times for oil absorption without losing its oil absorption capability. In this research,PP fiber,tire powder were mixed together to develop a composite material. It was found that the composite is capable of recovering great amounts of oil comparing to the any of its components. This composite can be used repeatedly for at least 100 times. Hence,the material cost for recovering 1 ton of spilled oil is about US $ 0.03,making it very competitive in comparison to other industrial oil absorbents on the market.

The mechanism and control of premature disbondment of three-layer polyethylene (3LPE) coatings have been the subjects of many research activities which are still going on. Also، the substitution of 3LPE with better coatings has been the aims of different research works and this paper is going to discuss it. Based on what is mentioned above، the quality and performance of two polyurethane and one polyurea coating samples were closely examined by running important standard tests including adhesion، cathodic disbondment، impact، bendability (flexibility)، water absorption، surfaces hardness، and dielectric strength. The results of cathodic disbondment tests of these three samples were compared with that of 3LPE coating. In this research، it was shown that polyurethane had better cathodic disbondment results than 3LPE coating. With reference to the fact that there is no report in the literature on the early disbondment of polyurethane from pipe surface، and that the coating is applicable on-site with one third thickness of 3LPE، polyurethane is recommended as a suitable substitution for 3LPE. Moreover، it was found the cathodic disbondment result of the polyurea was comparable with that of 3LPE. With reference to the same reasons argued for polyurethane، polyurea can be a good substitute for 3LPE as well.