Effect of EPDM structure on the properties of Babylon tire black sidewall compound

Abstract EN

The tire black sidewall is the outer surface that protects the casing against weathering.

It is formulated for resistance to weathering, ozone aging, abrasion, tearing and cracking, and for good fatigue life by using blends of natural rubber and cis-1.

4- butadiene rubber.

The tire black sidewall uses blends of natural rubber and cis-1.

4-butadiene rubber are used to achieve desired physical properties; however, use of these elastomers requires protection against ozone aging in order to maintain desirable properties over the lifetime of the tire.

Protection against ozone aging is of particular interest since reaction with these olefinically unsaturated elastomers results in polymer decomposition via chain scission.

Ethylene propylene diene terpolymer has proved most effective.

However, its use also results in a surface discoloration, and thus it can be used in sidewall compound when the tire appearance is also an important factor.

The best formulations are obtained in the presence of 40,50 phr EPDM to achieve desired physical properties.

Improved ozone resistance was obtained by using 40 and 50 phr of EPDM rubber in the compound there is no cracking throughout the life of the black sidewall compound.

Blends of NR/BR/ EPDM with up to 50 phr of EPDM rubber afforded adhesion levels greater than that of a natural rubber model sidewall.

Compounds containing NR / BR / EPDM blends with 2 phr of the 6PPD antiozonant provided the best dynamic ozone resistance.

Blending of EPDM with NR and BR enhances the abrasion resistance.

However, elongation at break and tear strength values are highest for those compounds having high contents of NR and Butadiene rubber.