Rubber Compounds Properties

A number of ingredients are added to both natural and synthetic rubber in order to obtain certain desirable properties.

Rubber compounds properties. Neoprene rubber is a general purpose compound that offers oil resistance and has good chemical stability. Sbr compounds have properties similar to those of natural rubber. The rubber materials selected by designers and technical buyers should meet all their application requirements. However the knowledge of rubber s physical properties and their measurement is critical for compound selection.

It is also able to remain flexible over a wide temperature range. The inherent physical characteristics of elastomers can be modified through compounding. Sbr features excellent resistance to brake fluids and good water resistance. A typical rubber formulation may have two or three different types of rubber adding up to 100 parts and then curatives fillers process stabilizers accelerators antiozonants antioxidants lubricants processing aids acid and base neutralizers and colorants to name a few.

The breakdown of natural rubber promotes viscoelasticity by extending or disentangling the polymer chains or by severing the chains. As noted above rubber compounds exhibit a wide range of properties resulting from differences in each material s formulation. This study aims to investigate the effect of carbon black structures on the mechanical properties of industrial tyre rubber compounds containing natural rubber nr and styrene butadiene rubber sbr. Sbrs primary custom molded application is the use in hydraulic brakes system seals and diaphragms with the major of the industry usage coming from the tire industry.

Different carbon black structures were used and characterised with respect to their rheological and physical properties it was found that the nr compound containing high structure black i e. Polymer 100 phr filler 30 60 phr. Basic elastomers are mixed with a variety of chemicals and ingredients to obtain desired physical properties. Rubber compound formulations have generally evolved over many years with new additives and fillers combined with old.

A rubber compound could be a combination of 3 to 15 different ingredients of thousands of different compositions and vendors. By convention mix formulations begin with the amount of the designated elastomer for instance natural rubber nr butadiene rubber br or styrene butadiene rubber sbr given as 100 parts by weight. This could not be further from the truth. The rubber properties chart below provides general information for various common elastomeric compounds and very general features of the most common elastomers.

Rubber rubber additives. A typical rubber formation based on parts per hundred is. Generally the many different grades of neoprene have a direct correlation to the actual percentage of neoprene in the compounds. Rubber compounds that crg supplies are capable of servicing a diverse range of temperatures from 73 c to 650 c and many are available in a wide range of durometers 40 80 shore a and thicknesses 1 32.