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Kautschuke

Heat Resistance, Water Resistance and Bin Storage Stability in CSM Hose Compounds

Achieving optimum heat and water resistance in chlorosulfonated polyethylene (CSM) based compounds has usually required the use of lead containing materials as acid acceptors. Bin storage stability, or specifically poor or marginal bin stability, can be an issue with some CSM formulations under hot, humid storage conditions. This paper discusses results showing hydrotalcite is a […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Thermal Stabilities of Electrical Properties of EBA/CB Composites

Changes in the electrical conductivity of carbon black filled EBA (ethylene butylacrylate copolymer) have been measured during thermal ageing and analysed. Above the composite melting temperature the conductivity increases steadily showing evidence of a relatively wide spectrum of relaxation times. This can be interpreted in terms of slow aggregation of carbon black clusters characterised by […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Autohesion to Rubber and Compounds – Measuring and Influencing Variables

The assembly tackiness of significance for the manufacture of complex elastomer products is subject to a number of influences. Crucial parameters are the compatibility, rheology, microstructure and chain mobility of the polymers, the chemical constitution of compound surfaces, ambient parameters and ageing behavior. A patented tackmeter has been developed for practice-relevant measurement of tackiness and […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

NMR for Product and Quality Control of Elastomers

NMR as a method has experienced continuous growth and development over the years and new fields of applications are steadily being explored. While progress in methods and applications of NMR to molecules in solution, solid materials, and medical imaging is reported in the scientific literature, developments in NMR with applications outside a laboratory often are […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Electrical and Mechanical Properties of Conductive Carbon Black Filled EVA, EPDM and their Blends

Carbon black filled conductive rubber composites have been derived from EVA, EPDM and their blends. The electrical and mechanical properties of the composites have been investigated. The critical concentrations for achieving high conductivity have been explained on the basis of the polarity of the base rubber. The temperature dependence of volume resistivity of the composites […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Investigation of Inhomogeneous Elastomers – A New Dynamic Indentation Method in Combination with Mechanical Imaging

In the present work a new indentation method for the investigation of inhomogeneous elastomers will be presented. With the help of special model systems the obtained data will be compared with conventional mechanical data. With an appropriate probe it is possible to obtain local resolution in the range of 50–100 μm, in a dynamic experiment […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Hysterese- und Relaxationsverhalten dynamischer Vulkanisate auf Basis von EPDM/PP

Zur Charakterisierung des mechanischen Verhaltens dynamischer Vulkanisate auf Basis von EPDM/PP-Mischungen wurde der Einfluß von Thermoplastgehalt und Konzentration des Vernetzungsmittels auf das Spannungs-Dehnungsverhalten sowie das Hysterese- und Relaxationsverhalten analysiert. Der Verlauf der Spannungs-Dehnungskurven, die Zugfestigkeit und die Bruchdehnung sowie die Kennwerte innere Spannung und bleibende Dehnung zeigten, daß die mechanischen Eigenschaften der dynamischen Vulkanisate sowohl […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Reinforcement of NR by Silica Generated In Situ: Comparison with Carbon Black Stock1

This paper describes the new mixing method of silica onto “green” natural rubber (NR) using the sol-gel reaction of tetraethoxysilane (TEOS) before curing. NR was subject to swelling by TEOS and the sol-gel reaction of TEOS in NR matrix was conducted by a base catalysis to obtain NR/in situ silica mix. The resulted NR/in situ […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Transition Behavior of Hydrogenated Acrylonitrile-Butadiene Rubber

Investigation of the glass transition temperature (Tg) and the tendency to crystallize in quiescent and stretched modes for hydrogenated acrylonitrile-butadiene rubber (HNBR) are reported. HNBR is a copolymer produced by the selective hydrogenation of the butadiene unit in acrylonitrile-butadiene rubber (NBR). In our consideration, HNBR was treated as a terpolymer of ethylene, acrylonitrile and 1-butene. […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Advanced Polymer Architecture

Fluoroelastomers were originally designed to provide a means of sealing in the most arduous applications where the consequences of failure are catastrophic. High part costs were acceptable in these early applications since production costs were considered largely unimportant compared to end use performance. These days fluoroelastomers are used in high volume automotive applications where the […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Application of Hygrothermally Decomposed Polyurethane in Rubber Recipes – Part 1: Natural Rubber (NR) and Nitrile Rubber (NBR) Stocks

In this work hygrothermally decomposed crosslinked polyurethane (PUR) was mixed up to 20 phr in standard natural (NR) and nitrile rubber (NBR) recipes. Their curing (CV system) and mechanical behavior were studied. It was found that addition of decomposed PUR resulted in faster cure and reduced Mooney viscosity in NR compounds. The effect was however […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Characterization of Carbon-Black Loaded Rubbers by the Use of the Dynamic Indentation Method

In the present paper a new dynamic indentation method for the investigation of carbon black loaded rubbers will be presented. For the characterization of these systems the Payne effect was used. A comparison of the results obtained by the indentation with the conventional method will be demonstrated. By creating mechanical images a local resolution of […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Verbesserung der Hitzestabilität von Kautschukvulkanisaten1

Die Verbesserung der Hitzestabilität von schwefelvernetzten Kautschukvulkanisaten ist eine Herausforderung für den Compounder bei der Entwicklung neuer Gummiartikel. Immer höhere Temperaturen im Motorraum, der Wunsch nach längerer Lebensdauer unter verschiedensten Einsatzbedingungen oder die Verkürzung der Vulkanisationszeiten durch höhere Vulkanisationstemperaturen erfordern neuartige Lösungen. Zur Vermeidung der Reversion oder Verbesserung der Hitzestabilität sind deshalb in den letzten […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Chemistry of EPDM Cross-linking1

Most EPDM applications require cross-linking, which is commonly achieved via accelerated sulphur vulcanization. Co-agent-assisted peroxide cure is applied for improving the thermal stability and/or the compression set of EPDM. Activated resol cure is only used for the dynamic vulcanization of PP/EPDM blends, i.e. for the production of TPVs. In this paper an overview is given […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

Elastizitätsmodul und Schichtenmorphologie von spritzgegossenen LCP-Platten

Spritzgegossene LCP-Formteile sind im hohen Maße anisotrop, wobei der Orientierungsgrad in Wanddickenrichtung strömungsinduziert variiert. Daraus resultiert die ausgeprägte Schichtenmorphologie der Formteile. Im Verarbeitungsprozeß läßt sich die Molekülorientierung stark beeinflussen, was sich direkt auf die mechanischen Eigenschaften auswirkt. Ebenfalls typisch für LCP ist, daß sich die Lichtreflexion des Materials im Einklang mit dem Orientierungsgrad ändert. In […] mehr...

28.April 2003 - Neues aus der Forschung

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