Naturkautschuk

Fachartikel

Preparation of Natural Rubber Based Thermoplastic Vulcanizates by Electron Induced Reactive Processing

In the present study, the rubber phase of the natural rubber (NR)/polypropylene (PP) blend were dynamically vulcanized during Electron Induced Reactive Processing (EIReP). A dramatic change in mechanical properties was observed after absorption of dose in the range from 100 to 350 kGy. In addition, we investigated the influence of polyfunctional monomers and molecular weight […] mehr...

2.Mai 2013 - Neues aus der Forschung

Kautschuke

Structural Analysis of Crosslinking Junctions of Vulcanized Natural Rubber by Solid-state NMR Spectroscopy Equipped with Field-gradient-magic Angle Spinning Probe

Field gradient-fast-magic angle spinning (FG-FMAS) probe, developed for solid-state NMR spectroscopy, was applied to investigate crosslinking junctions of vulcanized natural rubber. Resolution of 1H- and 13C-NMR spectra and correlation between 1H and 13C of the vulcanized natural rubber were investigated. Signals, appearing between 40 and 60 ppm, were well assigned by FG-FMAS-NMR spectroscopy. Based on […] mehr...

2.Mai 2013 - Neues aus der Forschung

Verarbeitungseigenschaften asiatischer und afrikanischer Naturkautschuksorten II – Kautschukmischungen und Vulkanisate

Processing properties of Asian and African natural Rubbers II – Rubber Mixtures and Vulcanisates

The prediction of rubber compound behaviour during industrial processing based on a few simple laboratory tests is not always a reliable. African and Asian natural rubbers were tested by ‘traditional‘ (Mooney viscometer, Wallace plastometer) and ‘new‘ (Rubber Process Analyser) instruments. The laboratory extrusion test was used to represent industrial processing machinery. Several convincing correlations were […] mehr...

18.September 2012 - Neues aus der Forschung

Fachartikel

Ein phänomenologischer Ansatz mit nur zwei freien Parametern zur Bestimmung des Ausheizgrades von Elastomerbauteilen

Über die Kenntniss des Ausheizgrades im Bauteil lassen sich Eigenschaften und Qualität des Produktes genauer bestimmen. Eine zuverlässige Vorhersage führt zu Einsparungen bei Zeit und Kosten, einhergehend mit einer Steigerung der Qualität. Die Genauigkeit der Simulation hängt von der Güte des Vernetzungs-Modells ab, dass heißt wie genau es z.B. die Vernetzungs-Isothermen darstellen kann. Vorgestellt wird […] mehr...

16.August 2007 - Neues aus der Forschung

Fachartikel

Studies on a Newer Process of Purification of a Vegetable Oil and Its Utilization as Factice

A newer method for bleaching of vegetable oil by charred saw dust has been discussed. The maximum colouring matter adsorbed ,Cmp ‘ (mg/m2) for oil on sawdust has been calculated. The negative value of DS indicates less disorder i.e. the crude oil contains more colourant and impurities before the bleaching process and these are decreased […] mehr...

19.Juni 2006 - Neues aus der Forschung

Institute & Verbände

Sulfur Curing of Natural Rubber in Presence of Zinc Di-n-Butylthiophosphate and 2-Mercaptobenzothiazole Combinations

The influence of combinations of zinc din-butylthiophosphate and 2-mercaptobenzothiazole on the process of sulfur curing of NR compounds as well as on the physical-mechanical properties of the vulcanizates was studied by using a the statistic design experiment (22 type). The results showed that the vulcanization behavior and the physical-mechanical properties are depended on both the […] mehr...

22.Mai 2006 - Neues aus der Forschung

Fachartikel

Development of a Rubber Pressure Moulding Technique for Fiber Reinforced Plastics

A rubber pressure moulding (RPM) technique is developed to prepare fiber reinforced plastic components (FRP) using glass fiber and epoxy resin. The technique is based on the matching die set, where the die is made of hard metal like steel and the punch from flexible rubber like materials. The use of a flexible rubber punch […] mehr...

26.April 2006 - Neues aus der Forschung

Effect of Heterogeneities on the Physical Properties

Conventional and Efficient Crosslinking of Natural Rubber

The scope of this article is to study the sulphur vulcanisation of natural rubber in the presence as accelerator of N cyclohexyl 2 benzothiazyl sulfenamide (CBS). Two series of compounds were prepared with conventional and efficient cured systems. Experimental results indicates that abstraction of allylic hydrogen and addition to the double bonds can act as […] mehr...

2.Dezember 2005 - Neues aus der Forschung

Kautschuke

Rheological Behavior of Blends of Natural Rubber and Hydrogenated Nitrile Rubber

The influence of dichlorocarbene modified natural rubber (DCNR) as a modifying agent on the rheological behavior of blends based on natural rubber (NR) and hydrogenated nitrile rubber (HNBR) was investigated. The binary blends of NR and HNBR showed a pseudoplastic flow behavior. The blends recorded a viscosity lower than both the constituents showing a behavior, […] mehr...

2.Dezember 2005 - Neues aus der Forschung

Kautschuke

FT-Rheology, a Tool to Quantify Long Chain Branching in Natural Rubber and its Effect on Mastication, Mixing Behaviour and Final Properties

Large Amplitude Oscillatory Shear on polymer melts at strain ratios between 2.5 and 10 provides variable stress signal distortion. The stresssignal distortion has been found to be sensitive only to the presence and level of long chain branching (LCB) and not to average molecular weight (AMW) and molecular weight distribution (MWD). Quantification of the signal […] mehr...

7.September 2005 - Neues aus der Forschung

Roh- & Zusatzstoffe

Evaluation of Physical and Electrical Properties of Chloroprene Rubber and Natural Rubber Blends

In the present study co-vulcanization of the blend containing CR and NR has been investigated both in gum and carbon black filled stocks. Significant improvements in the cure behavior of the stocks and the physical properties of the blend vulcanizates has been observed. Dielectric measurements were carried out and the variation of the dielectric properties […] mehr...

11.Mai 2005 - Neues aus der Forschung

Kautschuke

Purified Refinery Sludge as Process Aid in Sulphur Vulcanization of Natural Rubber

This paper reports the data obtained on an attempt at the utilisation of the sludge which is a dumped waste of petroleum refineries. This sludge after purification was used as a processing aid in the sulphur vulcanization of natural rubber where carbon black is used as filler. Different mixes, containing varying concentrations of aromatic oil/refinery […] mehr...

28.April 2003 - Neues aus der Forschung

Kautschuke

The Paradoxical Nature of Natural Rubber

The green nature of natural rubber is widely accepted, yet it is probable that many remain unaware of the significant contribution which natural rubber makes to global ecology. On the other hand, it can be argued that the main market for natural rubber (truck tyres) is a major contributor to destruction of the environment. Clearly […] 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

Evaluation of Natural Rubber and Cellulose II Compositions by Curing and Mechanical Properties

Rubber reinforcement increases if the domain size becomes less than 1 μm. Compositions of natural rubber and cellulose II were prepared by co-coagulation of natural latex and cellulose xanthate mixtures. The influence of increasing amount of Cel II, varying from 0 to 30 phr, on processing, curing and mechanical properties were studied. The use of […] mehr...

28.April 2003 - Neues aus der Forschung

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