Evaluation of ethylene-propylene-diene monomer (EPDM) aging in UV/condensation environment by principal component analysis (PCA)

Artificial weathering tests on ethylene-propylene-diene monomer (EPDM) were conducted in UV/condensation environment for different time periods up to 90 days. Principal component analysis (PCA) was used to evaluate the 11 aging parameters of EPDM including surface properties, crosslink density and mechanical properties. The results showed that EPDM aged quickly in the first 18 days of exposure and then slowed up. Among the 11 evaluating parameters, tensile stress at 100% elongation, surface tension and carbonyl content are strongly associated. The crosslink density is also well correlated with the hardness.