10 research outputs found

    Studies on coconut shell powder and crysnanoclay incorporated acrylonitrile-butadiene rubber/ styrene butadiene rubber (NBR/SBR) green nanocomposites

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    The development of commercially viable “green products” based on natural resources for both matrices and reinforcements for a wide range of applications is on the rise. This effort includes new pathways to produce natural polymers with better mechanical properties and thermal stability using nanotechnology and use of naturally occurring fillers such as lignocellulosic and hemicellulose to make biodegradable rubber composites. The blends of acrylonitrile butadiene rubber (NBR) and styrene butadiene rubber (SBR) with coconut shell powder (CSP) have been prepared by using a compounding technique in presence of different amounts of crysnanoclay (CN). The effect of CN loading on tensile properties, thermal properties, swelling behavior, and water uptake behavior were studied. Significant improvement of Young's modulus and tensile strength was observed as a result of addition of nanoclay to the rubber matrix especially at 10 wt% loading. Presence of CSP resulted in ahigher in water sorption but after incorporation of CN the water sorption tended to decrease. Thermal characteristics were performed using thermogravimetric analysis (TGA). TGA thermograms indicated that incorporation of CSP filler decreases the thermal stability of nanocomposites. The dispersion of CSP and CN in rubber matrix was analyzed from scanning electron microscopy. POLYM. COMPOS., 38:727–735, 2017. © 2015 Society of Plastics Engineer

    The Impact of the Implication of Balanced Scorecard Model (BSC) in Performance of the Post Company

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    Balanced scorecard model is a method to evaluate and control programs with adequate consistency. According to it, a certain organization is evaluated and controlled in terms of financial aspect, together with growth and learning, internal business processes and customer aspects. This research is practical in purpose and a descriptive inferential method has been used to collect data in addition to utilizing five-scale Likert questionnaire. In order to increase the accuracy of the study, all 320 employees of post company have been under evaluation. A one-sample t-test has been used to analyze the questions of the study. Furthermore, Friedman test has been used to investigate the differences among groups. The results of testing the hypotheses indicate the effect of growth and learning of the employees of post company, as well as internal business processes, customer and financial aspects on the performance of the post company. Moreover, Friedman test probing the differences among groups shows that internal business processes and customer variables have the most significant impact upon the performance of the post company, while growth and learning and financial aspects have the least significant effect on the performance of the post company

    Studies on coconut shell powder and crysnanoclay incorporated acrylonitrile-butadiene rubber/ styrene butadiene rubber (NBR/SBR) green nanocomposites

    No full text
    The development of commercially viable “green products” based on natural resources for both matrices and reinforcements for a wide range of applications is on the rise. This effort includes new pathways to produce natural polymers with better mechanical properties and thermal stability using nanotechnology and use of naturally occurring fillers such as lignocellulosic and hemicellulose to make biodegradable rubber composites. The blends of acrylonitrile butadiene rubber (NBR) and styrene butadiene rubber (SBR) with coconut shell powder (CSP) have been prepared by using a compounding technique in presence of different amounts of crysnanoclay (CN). The effect of CN loading on tensile properties, thermal properties, swelling behavior, and water uptake behavior were studied. Significant improvement of Young's modulus and tensile strength was observed as a result of addition of nanoclay to the rubber matrix especially at 10 wt% loading. Presence of CSP resulted in ahigher in water sorption but after incorporation of CN the water sorption tended to decrease. Thermal characteristics were performed using thermogravimetric analysis (TGA). TGA thermograms indicated that incorporation of CSP filler decreases the thermal stability of nanocomposites. The dispersion of CSP and CN in rubber matrix was analyzed from scanning electron microscopy. POLYM. COMPOS., 38:727–735, 2017. © 2015 Society of Plastics Engineer

    Synthesis of monodisperse anionic submicron polystyrene particles by stabilizer-free dispersion polymerization in alcoholic media

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    In this work, monodisperse polystyrene (PS) particles were synthesized in ethanol/water medium using sodium salt of styrene sulfonic acid and 2,2'-azobis(isobutyronitrile) as ionic comonomer and nonionic initiator, respectively. The polymerization was carried out at low agitation speed, and no stabilizer (or surfactant) was added to the polymerization medium. This polymerization system (stabilizer-free dispersion polymerization) was initiated as a homogeneous solution of monomer, comonomer, medium, and initiator. With the production of free radicals, polymerization developed into a heterogeneous system. The effect of various polymerization conditions on the size and size distribution of the obtained particles was evaluated. The experimental results showed that with an increase in ethanol content, the size of the particles increased while no significant change was observed in particle size distribution. Furthermore, with increasing ionic comonomer content, the size of the particles decreased and their size distribution became broader. Moreover, it was observed that addition of an electrolyte to the polymerization medium also increased the particles' size and broadened their size distribution. It is noteworthy to point out that the coagulation occurred in higher amounts of electrolyte. Finally, it is concluded that the polar component of Hansen solubility parameter of the polymerization medium affects the particle size and particle size distribution greatly
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