206 research outputs found

    Cure characteristics of recycled rubber powder filled styrene butadiene /chlorosulphonated polyethylene rubber blends

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    The effect of recycled rubber powder (RRP) on cure characteristics of styrene butadiene and chlorosulphonated polyethylene rubber blends (SBR/CSM) was investigated in the concentration range of 0 to 20 phr. Results indicate that the minimum torque and Mooney viscosity of the SBR/CSM rubber blends increase with increasing RRP loading whereas the scorch time and cure time exhibit a decreasing trend. Increasing RRP loading also gives SBR/CSM rubber compounds reduces the elongation at break but the tensile stress, M 200 (stress at 200% elongation) increases slightly.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

    The influence of dual active fillers on curing characteristics of elastomers based on natural rubber and chlorosulphonated polyethylene rubber

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    The effects of two type active filler (carbon black and silica) on the characteristics of elastomers based on natural rubber and chlorosulphonated polyethylene rubber blend blend (NR/CSM) were investigated. For cure studies, torque-time curves were registered at different temperatures (150, 160 and 170°C). It was estimated that higher curing temperature cause decreas of the cure plateau torque and lead to higher crosslinking rate constant.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

    Polymer based nanocomposites

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    Dispersions consisting of spherical CdS and α-Fe2O3 particles in the nanometer and sub-micron size range, as well as β-FeOOH nanorods with three different aspect ratios were prepared using colloidal chemistry methods. After incorporation of filler particles into polystyrene and poly(methyl methacrylate) matrices influence of filler particles on the thermal stability and the glass transition temperature of polymer matrices was studied in details. Significant influence of content, size and shape of filler particles on thermal properties of polymer matrices was found.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

    Thermal ageing and γ-radiation resistance of polyisoprene /chlorosulphonated polyethylene rubber blends

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    The effect of carbon black (average particle size 26nm) and wood flour (particle size from 300 to 400 μm) on thermal ageing and γ-radiation resistance of polyisoprene /chlorosulphonated polyethylene rubber blend (NR/CSM) was studied. The tensile strength of the aged samples was determined, after conditioning at 70°C during 72h. The radiation exposure of samples was performed at two doses: 212 and 400 kGy.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

    Design of nanoplatforms for electrochemical sensing of biomolecules

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    The aim of this study was to investigate thermal behavior of the new complex with formula [Cu(ala)cyc](ClO4)2∙2.5H2O. The complex was isolated and previously characterized by: elemental analysis (C, H, N), molar conductivity, UV/Vis and FTIR spectroscopy and magnetic measurements at room temperature. The sixcoordinate octahedral geometry around Cu(II) complexes was proposed. The experimental data suggested that the tetradentate ligand cyclam was coordinated to metals through four N donors and the amino carboxylate ligand coordinated via carboxylate ion. Investigate of thermal stability can be crucial in confirming the structure as well as in assessing the applicability of new compounds. The thermal properties of these complex have been investigated by thermogravimetric (TG) and differential thermal analysis (DTA). Therefore, TG-DTA analysis indicates that investigated complex decomposes exothermally in a single step in the range of 310 - 400 °C

    Production of liqueur from green walnuts using ionizing radiation

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    Liqueur from green walnuts is one of the many traditional medicines in folk medicine. It owes its healing properties to the main ingredient - unripe green walnuts. Green walnuts are a natural reservoir of vitamin C, vitamin B complex, vitamin E, calcium, potassium, magnesium, phosphorus, iron, zinc and iodine. Liqueur made from green walnuts is mostly used for problems with the thyroid gland, anemia, and various stomach infections. The liqueur is made by adding green walnuts to a container with sugar or honey and brandy, and leaving them to be exposed to the sun's rays for a period of 40 days. Photons accelerate the release of medicinal substances from green walnuts. This period of exposure is quite long, the quality of the liqueur is affected by the amount of solar energy delivered during that period, and contamination may occur during manual handling. All these problems can be solved by using photons from a radioactive gamma source instead of photons from the sun. The paper describes the process of obtaining liqueur from green walnuts using gamma radiation, as well as the comparison of the composition of liqueur obtained in the traditional way, with the effect of sunlight, and the application of an innovative method using gamma rays.RAD 2023 : 11th International Conference on Radiation Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023) 19–23.06.2023; Herceg Novi, Montenegr

    The influence of carbon black on curing kinetics and thermal aging of acrylonitrile–butadiene rubber

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    Elastomers based on a copolymer of butadiene and acrylonitrile (NBR) have excellent oil resistance but are very sensitive for degradation at very high temperatures. The aim of this applicative contribution was to determine the effect of high abrasion furnace carbon black with primary particle size 46 nm on aging properties of elastomeric materials based on NBR as network precursor. The curing kinetics was determined using the rheometer with an oscillating disk, in which the network formation process is registered by the torque variation during time. The vulcanizates were obtained in a hydraulic press at 150 °C. The mechanical properties of elastomeric composites were determined before and after thermal aging in an air circulating oven. The reinforcing effect of the filler particles was assessed according to mechanical properties before and after aging

    Non-isothermal dehydration of equilibrium swollen radiolytically sinthesized Fe3O4 – PVA ferrogel nanocomposite

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    In this study, the Fe3O4 - PVA ferrogel nanocomposite was synthesized by gamma irradiation. Obtained ferrogel had greater swelling capacity and activation energy of dehydratation as measured by thermogravimetric analysis under non-isothermal conditionsPhysical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

    Efficient synthesis and detailed thermal studies of zinc phthalocyanine

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    A facile and efficient, one step synthesis of macrocyclic molecule zinc phthalocyanine (ZnPc), was proposed. Dark violet crystals of ZnPc dye were obtained in high boiling point solvent of dimethylformamide (DMF) in the presence of 2,2,6,6-tetramethylpiperidine (TMP) as a catalyst. Detailed thermogravimetric and kinetic analysis revealed high thermal stability of the investigated compound

    Thermo-chemical conversion of cigarette butt filters waste through pyrolysis process using thermal analysis techniques

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    Thermo-chemical conversion of cigarette butt filters (CBF) waste was investigated using various thermal analysis techniques (simultaneous TG-DTG-DTA and DSC methods) at different heating rates in an inert atmosphere. Thermo- and thermo-physical properties of waste material were discussed, from the point of view of chemical structure and the influence of experimental parameters on the conversion process. It was established that acetyl groups of plasticizer (triacetin) interact with cellulose acetate through dipolar interactions and hydrogen bonding’s. Influence of these polar interactions can affect the position of glass transition temperature, Tg, of CBF. Based on estimated value of Tg from DSC analysis, it was found that cellulose acetate present in CBF has degree of substitution equals to 2.8, where the presence of cellulose triacetate was confirmed. It was assumed that an increase of degree of substitution leads to decline in the crystallinity. A decline of crystal-linity causes the reduction of hydroxyl groups, leading to less organized chains, and whereby decreasing of inter-molecular interactions through hydrogen bond-ing. Based on the examination of thermophysical characteristics of the tested ma-terial, it was found that both, the heat capacity and the thermal inertia of material linearly increase with temperature, during pyrolysis progression. It was concluded that the type of bio-char produced in this process would have a large capacity to store the heat, which may depend on the formed particles size diameter and poros-ity. Furthermore, it was inferred that magnitude drops of thermal conductivity, κ, after Tg depends on the material fibrillatio
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