Crosslink Density and Distribution of New, In-Service, and Artificially Aged Tires

The goal for the United States Department of Transportation - National Highway Traffic Safety Administration (NHTSA) is to develop an aged endurance test for tires. ² The

artificial aging will focus on the internal tire components such as the belt edges, which is an important area for tire durability. Aerobic aging of tire belt-coat (also referred to as

“skim” or “wirecoat”) compounds led to increased crosslink densities. The belt-coat compounds’ crosslink distribution also changes during aerobic aging. The report will

place emphasis on the rates of change observed in the measured properties of tires collected from Phoenix, the magnitude of the properties (measured or predicted) of an

average 4 year old tire in Phoenix, and the ability of various artificial aging methods to match these rates and magnitudes within the same model of tire.