The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
A. Bantjes - One of the best experts on this subject based on the ideXlab platform.
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Vulcanization of Butadiene Rubber by Means of Cyclic Disulfides. 3. A 2D Solid State HRMAS NMR Study on Accelerated Sulfur Vulcanizates of BR Rubber
Macromolecules, 1999Co-Authors: A.j.r.l. Hulst, R.m. Seyger, J.p.m. Van Duynhoven, L. Van Der Does, Jacobus W.m. Noordermeer, A. BantjesAbstract:Sulfur vulcanizates of high cis-butadiene rubber (BR) obtained by using different curing systems such as conventional (CBS) and efficient sulfur (sulfur donor, TMTD) Vulcanizing systems were invest...
H Ismail - One of the best experts on this subject based on the ideXlab platform.
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Enhancing the thermal stability of natural rubber/recycled ethylene–propylene–diene rubber blends by means of introducing pre-vulcanised ethylene–propylene–diene rubber and electron beam irradiation
Materials & Design, 2014Co-Authors: Hadeer Nabil, H IsmailAbstract:Abstract Most rubber materials are subjected to oxidation. The rate of oxidation depends on the type of rubber, processing method, and end-use conditions. The oxidation of rubber can result in the loss of physical properties, such as tensile strength, elongation, and flexibility. Hence, the service life is determined by oxidation stability. Thermal properties are relevant to the potential use of polymeric materials in many consumer oriented applications. Thermo-oxidative ageing and thermogravimetric analysis (TGA) have been proven to be successful techniques in determining the thermal stability of polymers and polymer blends. In this article, preparation of a series of natural rubber/recycled ethylene–propylene–diene rubber (NR/R-EPDM) blends is described. Processing of the blends, by means of introducing pre-vulcanised EPDM and electron beam (EB) irradiation, was carried out. Two thermal analysis methods, namely thermo-oxidative ageing and thermogravimetric analysis, were conducted. The results indicated that pre-vulcanising EPDM for 1.45 min (ts − 2) is sufficient to gain the optimum retained tensile and elongation at break. It was simultaneously observed that the introduction of pre-vulcanised EPDM increased decomposition temperature and activation energy by showing optimum values at a pre-vulcanising time of 3.45 min (ts). In the latter study, the retained properties increased after EB irradiation. The results can be verified by the thermal decomposition temperature and their activation energy. The obtained TG profiles and the calculated kinetic parameters indicated that introducing EB irradiation into the blends enhanced their thermal stability. The thermal stability of the blends, processed by these two means, is significantly enhanced; irrespective of pre-vulcanising time or irradiation dose.
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Properties of natural rubber/recycled ethylene–propylene–diene rubber blends prepared using various Vulcanizing systems
Iranian Polymer Journal, 2014Co-Authors: Hadeer Nabil, H Ismail, A R AzuraAbstract:The role of various Vulcanizing systems on the curing characteristics, mechanical properties, morphology and dynamic mechanical analysis of natural rubber and recycled ethylene–propylene–diene rubber blends was investigated. Accelerated sulfur-Vulcanizing systems (semi-EV and EV), peroxide, and mixed sulfur/peroxide-Vulcanizing systems (semi-EV/peroxide and EV/peroxide) were observed and compared. The blends were processed on a two-roll mill, and a fixed amount of carbon black was also incorporated. Amongst the blends, accelerated sulfur-Vulcanizing systems exhibited higher torques, state of cure, tensile strength and elongation-at-break, in comparison with the peroxide-Vulcanizing system, whereas the tensile modulus, hardness and cross-link density showed lower trend. In the mixed sulfur/peroxide-Vulcanizing systems, it showed intermediate behavior to the individual sulfur- or peroxide-Vulcanizing systems. This was associated to the interference of peroxide during the cross-linking formation. SEM micrographs of semi-EV-Vulcanizing system exhibited more roughness and cracking path indicating that higher energy was required towards the fractured surface. The high cross-link density observed from the swelling study could be verified from the storage modulus ( E′ ) where peroxide vulcanized blends provided a predominant degree of cross-linking followed by semi-EV, semi-EV/peroxide, EV and EV/peroxide-Vulcanizing systems, respectively. The glass transition temperature ( T _g) depicted at maximum peak of mechanical loss factor (tan δ _max), indicating that semi-EV-Vulcanizing system showed highest T _g value. The T _g values can be ordered as semi-EV > peroxide > semi-EV/peroxide > EV > EV/peroxide-Vulcanizing systems. The T _g of rubber vulcanizates can be increased due to the restriction of molecular movement such as cross-link density.
A.j.r.l. Hulst - One of the best experts on this subject based on the ideXlab platform.
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Vulcanization of Butadiene Rubber by Means of Cyclic Disulfides. 3. A 2D Solid State HRMAS NMR Study on Accelerated Sulfur Vulcanizates of BR Rubber
Macromolecules, 1999Co-Authors: A.j.r.l. Hulst, R.m. Seyger, J.p.m. Van Duynhoven, L. Van Der Does, Jacobus W.m. Noordermeer, A. BantjesAbstract:Sulfur vulcanizates of high cis-butadiene rubber (BR) obtained by using different curing systems such as conventional (CBS) and efficient sulfur (sulfur donor, TMTD) Vulcanizing systems were invest...
Žáček Jan - One of the best experts on this subject based on the ideXlab platform.
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Design of steel foot guideway for Vulcanizing press
Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016Co-Authors: Žáček JanAbstract:Bachelor‘s thesis is focused in design of guideway construction for automatic transfer of steel foot into the station of Vulcanizing press. The theoretical part describes historical milestones of making footwear, including machinery, with a focus on vulcanization proces. The design part contains different alternative solutions which meet the conditions specified by the manufacturer of this shoemaking machine for which is the guideway designed. Subsequently is chosen the most appropriate solution that consists of a system of pulleys, toothed belt and line formed by ball transfer units
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Design of steel foot guideway for Vulcanizing press
Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016Co-Authors: Žáček JanAbstract:Bakalářská práce je zaměřena na návrh pojezdové konstrukce pro automatické přemístění ocelové nožky do stanice vulkanizačního lisu obuvi. Teoretická část práce popisuje historické mezníky výroby obuvi včetně strojního zařízení se zaměřením na vulkanizaci. Konstrukční část obsahuje jednotlivé varianty řešení, které splňují podmínky dané výrobcem obuvnického stroje, pro něž je pojezd určen. Následně je vybráno nejvhodnější řešení, které sestává ze systému řemenic, ozubeného řemene a dráhy tvořené kuličkovými hnízdy.Bachelor‘s thesis is focused in design of guideway construction for automatic transfer of steel foot into the station of Vulcanizing press. The theoretical part describes historical milestones of making footwear, including machinery, with a focus on vulcanization proces. The design part contains different alternative solutions which meet the conditions specified by the manufacturer of this shoemaking machine for which is the guideway designed. Subsequently is chosen the most appropriate solution that consists of a system of pulleys, toothed belt and line formed by ball transfer units.
Hadeer Nabil - One of the best experts on this subject based on the ideXlab platform.
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Enhancing the thermal stability of natural rubber/recycled ethylene–propylene–diene rubber blends by means of introducing pre-vulcanised ethylene–propylene–diene rubber and electron beam irradiation
Materials & Design, 2014Co-Authors: Hadeer Nabil, H IsmailAbstract:Abstract Most rubber materials are subjected to oxidation. The rate of oxidation depends on the type of rubber, processing method, and end-use conditions. The oxidation of rubber can result in the loss of physical properties, such as tensile strength, elongation, and flexibility. Hence, the service life is determined by oxidation stability. Thermal properties are relevant to the potential use of polymeric materials in many consumer oriented applications. Thermo-oxidative ageing and thermogravimetric analysis (TGA) have been proven to be successful techniques in determining the thermal stability of polymers and polymer blends. In this article, preparation of a series of natural rubber/recycled ethylene–propylene–diene rubber (NR/R-EPDM) blends is described. Processing of the blends, by means of introducing pre-vulcanised EPDM and electron beam (EB) irradiation, was carried out. Two thermal analysis methods, namely thermo-oxidative ageing and thermogravimetric analysis, were conducted. The results indicated that pre-vulcanising EPDM for 1.45 min (ts − 2) is sufficient to gain the optimum retained tensile and elongation at break. It was simultaneously observed that the introduction of pre-vulcanised EPDM increased decomposition temperature and activation energy by showing optimum values at a pre-vulcanising time of 3.45 min (ts). In the latter study, the retained properties increased after EB irradiation. The results can be verified by the thermal decomposition temperature and their activation energy. The obtained TG profiles and the calculated kinetic parameters indicated that introducing EB irradiation into the blends enhanced their thermal stability. The thermal stability of the blends, processed by these two means, is significantly enhanced; irrespective of pre-vulcanising time or irradiation dose.
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Properties of natural rubber/recycled ethylene–propylene–diene rubber blends prepared using various Vulcanizing systems
Iranian Polymer Journal, 2014Co-Authors: Hadeer Nabil, H Ismail, A R AzuraAbstract:The role of various Vulcanizing systems on the curing characteristics, mechanical properties, morphology and dynamic mechanical analysis of natural rubber and recycled ethylene–propylene–diene rubber blends was investigated. Accelerated sulfur-Vulcanizing systems (semi-EV and EV), peroxide, and mixed sulfur/peroxide-Vulcanizing systems (semi-EV/peroxide and EV/peroxide) were observed and compared. The blends were processed on a two-roll mill, and a fixed amount of carbon black was also incorporated. Amongst the blends, accelerated sulfur-Vulcanizing systems exhibited higher torques, state of cure, tensile strength and elongation-at-break, in comparison with the peroxide-Vulcanizing system, whereas the tensile modulus, hardness and cross-link density showed lower trend. In the mixed sulfur/peroxide-Vulcanizing systems, it showed intermediate behavior to the individual sulfur- or peroxide-Vulcanizing systems. This was associated to the interference of peroxide during the cross-linking formation. SEM micrographs of semi-EV-Vulcanizing system exhibited more roughness and cracking path indicating that higher energy was required towards the fractured surface. The high cross-link density observed from the swelling study could be verified from the storage modulus ( E′ ) where peroxide vulcanized blends provided a predominant degree of cross-linking followed by semi-EV, semi-EV/peroxide, EV and EV/peroxide-Vulcanizing systems, respectively. The glass transition temperature ( T _g) depicted at maximum peak of mechanical loss factor (tan δ _max), indicating that semi-EV-Vulcanizing system showed highest T _g value. The T _g values can be ordered as semi-EV > peroxide > semi-EV/peroxide > EV > EV/peroxide-Vulcanizing systems. The T _g of rubber vulcanizates can be increased due to the restriction of molecular movement such as cross-link density.
