Rubber surface deterioration

Weathering - A surface deterioration of a rubber article during outdoor... 

It should be pointed out at this stage that the formation of an oily degraded surface layer is not necessarily a beneficial feature. If the layer is readily removed from the rubber, then further deterioration can proceed rapidly. Indeed, if in the early stages of decomposition, the rubber is rendered softer and weaker, it will be torn away more easily and the rate of wear will be correspondingly greater than in the absence of general molecular scission. On the other hand, if the liquidlike film is viscous, tarry, and adhesive, it appears to be retained on the rubber surface to act as a protective layer. The rate of wear is then much reduced. 

Physical Form Straw colored liquid or 70% active powder A low volatility, non-discoloring, general purpose antioxidant which offers good resistance to hardening amd general surface deterioration of rubber and latex articles. 

Mud temperatures of 150° can present critical suction problems. Under low pressure or vacuum existing in the cylinder on the suction stroke, the mud can boil, hence decreasing the suction effectiveness. Furthermore, hot mud accelerates the deterioration of rubber parts, particularly when oil is present. Large mud tanks with cooling surfaces usually solve the problem. 

Materials used to protect vulcanisates from deterioration, including surface coatings as well as the ingredients added to the rubber at the mixing stage. See Antioxidant, Antiozonant, Paraffin Wax. 

The ideal measure will be that the rubber lined surface is always kept wet with water in order to arrest the likely deterioration from ultraviolet rays and ozone attack during storage. 

Temperature is a significant factor friction may raise the temperature of the surface layers to the point where they become subject to chemical attack. Abrasion causes deterioration of many materials, especially of rubber (tire treads), where it can be offset by a high percentage of carbon black. Other materials subjected to abrasion in their service life are textiles (laundering), leather and plastics (shoe soles, belting), and house paints and automobile lacquers (airborne dust, grit etc.). 

Test method for rubber deterioration Surface cracking. 

Processing oils in a rubber formulation serve primarily as a processing aid. Oils fall into one of three primary categories paraffinic, naphthenic, and aromatic. The proper selection of oils for inclusion in a formulation is important. If the oil is incompatible with the polymer, it will migrate out of the compound with consequent loss in required physical properties, loss in rubber component surface properties, and deterioration in component-to-component adhesion, as in a tire. The compatibility of an oil with a polymer system is a function of... 

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