Advanced Materials Research Vol. 1119

Abstract: The purpose of this research was to study water retention properties of superabsorbent hydrogel based on poly (acrylamide)/biofiller hydrogel and urea liquid fertilizer, by solution polymerization. Kenaf fiber (KF) was used as biofiller and the preparation of the poly (acrylamide)-grafted-kenaf fiber (PAAm-g-KF) hydrogel was carried out by polymerizing the monomer. Urea fertilizer was employed as polymerization media. N,N’-methylene bisacrylamide (MBA) was used as a crosslinker and ammonium persulfate (APS) as an initiator. Water retention of the hydrogel was studies in soil with three different samples (Controlled, PAAm Hydrogel, PAAm-g-KF). The PAAm-g-KF was also applied to agricultural field. The results show that PAAm-g-KF greatly improved water retention in the soil and agricultural field.

Abstract: This paper presents the results of a study carried out to examine electrical characteristics of high voltage Silicone Rubber (SIR) insulators under weather pollution conditions. The specimens of SIR with and without Alumina tri-hydrate (ATH) filler have been chemically prepared. The AC (50 Hz) surface aging of SIR specimens have been evaluated under salt fog chamber. Furthermore, the relationship between the leakage current and time to failure for SIR specimens with various concentrations of ATH filler under different weather pollution conditions has been measured in this work.

Abstract: Much published literature on the way in which phase morphology and filler distribution affect blend properties is contractor or confusing The blending of two or more polymers by physical or chemical means may improve a variety of physical and chemical properties of the constituent polymers. The effect of different modes of filler addition on dispersion and viscosity of Epoxidisd Natural Rubber (ENR) and cis 1,4 –polybutadiene rubber (BR) has been studied. Experiments were carried out to elucidate the relationship and to determine whether the use of special mixing technique and compatabilizers might have a beneficial effect on Epoxidised Natural Rubber: Butadiene Rubber (ENR:BR) blend properties. The findings indicated blending times for combining Silica, BR and ENR was rather difficult even a close viscosity of each rubber was applied. Results indicated a high degree of compatibility with fine structured blends being quickly and easily produced with compound containing compatibilizer than compound with any. Hence, a high viscosity and poor filler dispersion was obtained with all mixing techniques applied except with the one with the coupling agent.

Abstract: Recent studies on cream of rubber extract (HB) have significantly showed skin improvement results, however, there were color and odor issues. To solve the problems, we successfully produced ultra-fine cellulose acetate (CA) fiber mats (electrospun fibers) containing 1-5 wt% extracts of rubber from Hevea brasilensis without any chemical additions. This new approach has in fact revealed the desired material and biomolecule immobilization. The SEM photographs show the straight and even shaping of the processed HB-CA fibers. The average fiber diameters of the HB-CA fibers ranged between 415 and 585 nm. Moreover, HB-CA solutions containing 1-3% HB extract resulted in a more consistent texture of the fiber mats. This was the first time to produce nanofibers using only rubber extract and cellulose acetate without any other potentially bioactive components involved. This innovation did not only solve the initially addressed color and odor issues, but also provided a new purified material of very small fibers which allows better control of its bioactivity due to the fact that less chemical substances are involved. Its highly interesting characteristics, such as high surface areas to mass ratio, high porosity et al make this result an excellent potential candidate e.g. facial masks, and other innovative products in the field of cosmetics and pharmaceutical industry. Further research is needed and highly promising.

Abstract: Powdered polychloroprene rubber (PCR-244) was prepared by the direct condensation, and the influence of agglomerator kinds and dosages on powdering of PCR-244 were investigated, including trivalent salt (aluminum chloride), divalent salt (magnesium sulfate, calcium chloride) and monovalent salt (sodium chloride, potassium chloride). The result showed that powder chloroprene rubber could be used as adhesive material that calcium chloride was used as agglomerator.

Abstract: The factors that influence environmentally-friendly powder rubber powdering are introduced. Types and dosage of isolation agent, types and dosage of coagulant, environmental antioxidant, condensation temperature, stirring speed on the effect of powder rubber are examined. Thus a simple method to prepare environmental powder rubber is provided.As a physical variation of traditional bulk rubber, powder rubber can change the situations that high energy consumption and high labor intensity of the former. And it also can make the mixing process become continuous, automated, energy-saving and so on. In recent years, with the progress of rubber processing industry, the demand of powder rubber increases rapidly. And there is a intense requirement of supplying environmentally-friendly powder rubber^[1-3]. So it is very important to do this experiment.

Abstract: Cassava peel is one of agricultural waste that abundantly found in environment. One approach to manage this waste is to apply it as filler in natural rubber latex. In this work, the cassava peel waste (CPW) was powdered and dispersed in alkanolamide-water dispersion system to modify its surface. The amount of fillers used was 0, 5, 10, 15, 20 and 25 phr (part per hundred rubber) and loaded in natural rubber latex (NRL) formulation system. The products then were formed by dipping method after the NRL formulation was pre-vulcanized at 70°C. The observed parameter includes crosslink density, tensile strength, tensile modulus and elongation at break. Scanning Electron Microscope (SEM) was used to study the morphology of tensile fracture in NRL film. The results show that 10 phr loading of modified fillers increases the crosslink density, tensile strength, and tensile modulus but decreases the elongation at break. SEM study also reveals that higher filler loading above 10 phr will create the agglomeration in rubber matrix.

Abstract: Waste pre-vulcanized nitrile latex (WPNL), obtained from nitrile glove dipping tank was blended at different ratios with concentrated ENR latex processed via ultrafiltration and designated as ENRLC-SP20 and ENRLC-SP50, respectively, with the number indicating, the percentage of WPNL incorporated into the blend. The blends were prepared in the latex stage and subsequently processed into dry rubber. The rubbers were then blended with virgin nitrile rubber (NBR) at various ratios and the curing characteristics and physical properties of the blends were evaluated. The results showed the maximum torque (MH) decreases while the minimum torque (ML) increases with increasing level of SP 50 rubber. Using higher concentrations of SP-50, the results showed slight reductions in the cure (t90) and scorch time (ts2), respectively. It was also found that by increasing ratio of ENRLC-SP20 and ENRLC-SP50 improves the heat ageing resistance of NBR blends at 100°C as evidenced by the higher percentages in retention of the blends, compared to the control compound.

Abstract: Titanium Dioxide is an important material that is used in many industrial applications such as photo-catalysis, glass-defogging, self-cleaning, waste water purification and anti-bacterial sterilization. The strong photo-catalysis of TiO₂, and therefore its ability to decompose dirt and organic contaminants makes it an excellent top-protective layer candidate for CSP reflectors. The aim of this study consists of the deposition of a transparent and hydrophilic TiO₂ layer on top of the Concentrated Solar Power (CSP) mirrors without altering their specular reflectance. The strong photo-catalysis and hydrophilicity of TiO₂ will decompose the dirt and organic matter on the surface of the mirrors, which would be cleaned away from the reflectors’ surface by rain, therefore minimizing the use of water for cleaning the CSP mirrors.In this study, polycrystalline anatase TiO₂ layers were deposited on glass substrates with different thicknesses. The contact angle measurements show that the hydrophilicity of TiO₂ increases with increasing surface roughness, with Water Contact Angle (WCA) of 52°and 30° for 48 nm and 100 nm, respectively. Super-hydrophilicity (WCA < 5°) was achieved for thicker TiO₂ layers, with WCA of 8° and 1° for 177 nm and 220 nm, respectively. The deposition of a 48 nm-thick TiO₂ layer on glass showed a high transmittance in the visible and Near Infrared (NIR) range (75%), whereas the transmission decreased with increasing thicknesses of TiO₂. Therefore, a TiO₂ layer of 48 nm thickness is suggested in this study as a hydrophilic top-protective layer since it preserved the specular reflectance of the mirrors (97.5%) in the NIR range, compared to 98.6% without the TiO₂ layer.

Abstract: In the present investigation artificial neural network (ANN) approach was used for the prediction of wear and friction properties of low cost near beta titanium alloy β solution treated condition. The input parameters are load, track diameter and β solution treated temperature and output parameters are %weight loss, coefficient of friction and temperature generated between the pin and disc. In order to get the best model, different parameters like number of layers, number of hidden neurons, and transfer functions are changed. The data obtained in sliding wear tests were divided into two sets training data and testing data. A neural network was trained using a training data set and was validated using test data. The best network for prediction of tribological properties of these β solution treated specimens was 3-[11]₁-[9]₂-3 layer recurrent with purelin transfer function and trainlm is training function. The percentage error for %weight loss, coefficient of friction and temperature are 2.8, 1.7 and 5.3 respectively.