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Showing 1 to 20 of 38 for “"Polyisoprene"”.
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Formulation and Burning Behaviour of Fire Retardant Polyisoprene Rubbers
… knowledge base for fire retardant approaches for polyisoprene rubber, characterising unmodified compounds, formulating and studying fire retarded compounds for use within suspension and anti-vibration mounting systems. Materials have been prepared on a bench scale and evaluated for physical …
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Tearing of Black-Filled (N660) Synthetic Polyisoprene Rubber Vulcanizates at Various Temperatures
Natural rubber (NR) has outstanding tack and strength in the unvulcanized state and high tensile and tear strength when vulcanized. These features are attributed to its ability to crystallize rapidly on straining. Synthetic isoprene rubber (IR), synthesized employing a stereospecific catalyst, …
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Some Aspects of the Oxidative Stability of Cis-1, 4-Polyisoprene Vulcanizates
… vulcanizates prepared from unstabilized cis-1,4- polyisoprene. Initially the effect of specimen thickness was investigated to ensure that diffusion controlled oxidation did not occur during the course of the oxygen uptake measurements. A comparison of several types of sulphur vulcanizates …
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Deformation induced molecular behavior of Cis 1,4-polyisoprene and its nanocomposites monitored by solid-state NMR
… in the molecular motion and architecture of polyisoprene, polyisoprene-clay composites and polyhedral oligomeric silsesquioxane (POSS) nanofillers. The high frequency relaxations monitored by NMR are sensitivity to changes in the environment of polyisoprene chains as a function of compressive …
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Mechanical properties of gels formed by nickel and cobalt complexation with histamine-grafted polyisoprene and polystyrene in non-aqueous solvents
… pathways. In this work, we synthesized several polyisoprene-graft-histamine gels in toluene, coordinated by Ni²⁺ and Co²⁺ ions. In addition, we synthesized polystyrene-graft-histamine-Ni(OH)₂ composites in DMF, with Ni(OH)₂ nanoparticles nucleated and grown in situ upon the addition of a …
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Novel Approaches To The Synthesis of Clicked Block Copolymers
… of block copolymers, namely polystyrene-b-polyisoprene, using azide-alkyne click chemistry techniques is investigated. Both azido and alkyne-terminated polystyrene were synthesized using ATRP. Azido-terminated polystyrene was synthesized via a substitution reaction between NaN3 and …
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The Vulcanisation of Elastomers with Bis (Dialkyl) Thiophosphoryl Disulphides
… a sulphur donor vulcanising system for cis-1,4-polyisoprene. It is shown that the network structure consists of polyand disulphidic crosslinks at early stages of cure, simplifying at optimum cure to monosulphidic crosslinks. Pendent accelerator groups bound to the rubber molecule form at early …
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Synthesis of Well-Defined Multi-End Functionalized Polymers via Living Anionic Polymerization
… of multi-end functionalized polystyrene and polyisoprene additives with a wide range of molecular weights, carrying 1 to 3 fluoroalkyl groups that have been prepared by end capping the living chain ends of polymers prepared via anionic polymerization reactions. The resulting polymers have a …
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Structure-property behavior of elastomeric telechelic ionomers in bulk and solution
… The bulk mechanical properties of carboxylated polyisoprene telechelic ionomers were also investigated. The sulfonated polyisobutylene telechelic ionomers are available in three different molecular architectures - linear monofunctional, linear difunctional, and three-arm star trifunctional. …
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Konformation und Wechselwirkung von Elastomeren, adsorbiert an Ruß und Silica - untersucht durch transversale 1H NMR Relaxation
… und eine gefällte Kieselsäure. Die verwendeten Polyisoprene wurden anionisch synthetisiert und für die Adsorption auf Silica bis zu 10 epoxidiert. <br>Ein bekanntes Modell mit drei Relaxationskomponenten wurde erweitert auf 4 Komponenten: Kettenenden, Polymersegmente in Schlaufen, kurzen Brücken …
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Dynamic aspects of adsorbed polymer layers: Evidence of glass-like transitions
… poly(methyl methacrylate) (hPMMA & dPMMA), and polyisoprene (PI) in control experiments.
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Applications of high resolution solid state carbon-13 NMR to the study of multicomponent polymer systems
… for the samples cast from a poor solvent for polyisoprene {MEK) in contrast to samples cast from a good solvent of polyisoprene (hexane). For the polymer blends of poly(vinylidene fluoride), the level of molecular intermixing was reflected through the degree of ¹³C NMR signal attenuations of …
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Plant proteins as multifunctional additives in polymer composites
… poly(vinyl alcohol) (PVA) and synthetic cis-1,4-polyisoprene rubber (IR). The proteins were hydrolyzed and dispersed in the polymer matrix, where they cooperatively self-assembled into nanostructures called amyloids. Amyloids have the potential for high rigidity and stability due to high β-sheet …
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Further investigations of the prevulcanization of natural rubber latex
… behaviour of NR latex and synthetic cis-polyisoprene latex. It has been suggested that the indigenous vulcanization accelerators and activators present in NR latex act as additional vulcanizing accelerators and therefore increase the rate of prevulcanization.
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Studies on the Preparation, Immobilization, and Luminescence Properties of Zinc Oxide (ZnO)Quantum Dots
… The quantum dots that were immobilized in polyisoprene (PI) through chemiluminescence (CL) analyses were found to be stable and were capable of continuing their luminescence properties with extended uses and long- term storage. Linear calibration curves were acquired for concentration of …
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Study of Immobilizing Cadmium Selenide Quantum Dots in Selected Polymers for Application in Peroxyoxalate Chemiluminescence Flow Injection Analysis
… sizes were synthesized for immobilizing in polyisoprene (PI), polymethylmethacrylate (PMMA), and low-density polyethylene (LDPE). The combinations of QDs and polymer substrates were evaluated for their analytical fit-for-use in applicable immunoassays. Hydrogen peroxide standards were …
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Aminopyridinato-Ligand-Stabilized Lanthanoid Complexes: Synthesis, Reactivity, Ethylene and Isoprene Polymerization
… We could even obtain isotactically enriched 3,4-polyisoprene through appropriate choice of the polymerization conditions (cocatalyst, polymerization temperature). The aminopyridinate-stabilized diamide of scandium can polymerize isoprene in the presence of anilinium borate and trialkylaluminium …
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Studio di componenti del lattice di Euphorbia characias
… revealed the characteristic of the cis- 1,4-polyisoprene typical of natural rubber. The enzyme catalyzing the rubber molecule elongation is cisprenyltransferase called “rubber transferase”. We cloned the cDNA encoding for the E. characias rubber transferase by RT-PCR. The cDNA contains an …
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Synthesis and characterization of linear and star-branched butadiene-isoprene block copolymers and their hydrogenated derivatives
… polyethylene segments, while the central polyisoprene blocks resulted in the formation of amorphous alternating rubbery copolymers of propylene-ethylene. The hard semicrystalline blocks form morphological domains that serve as physical crosslinking and reinforcement sites. The presence of …
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Incorporating Recycled Plastics in Asphalt Binders and Mixtures
… (rLDPE) in asphalt binder. Compatibilizers with polyisoprene (PI) and polybutadiene (PBD) backbones synthesized with polyethylene-block-polyethylene (glycol) (PEPEG) at two different molecular weights were tested. The effect of unreacted Maleic anhydride (MAH) in the compatibilizers was also …
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