Performance Prediction of Antiaging Aliphatic Polyurethane Topcoat

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Polyurethane coatings offer excellent durability but their aging behavior is difficult to quantify.
• Accelerated testing is crucial for predicting the service life of protective coatings.

Purpose of the Study:

• To develop a quantitative method for evaluating the aging of aliphatic acrylic polyurethane topcoats.
• To correlate surface chemical changes with glossiness degradation during accelerated aging.

Main Methods:

• Accelerated cyclic aging tests were performed on two polyurethane topcoats.
• Infrared spectroscopy was used to monitor changes in chemical structure, specifically carbonyl content.
• Glossiness measurements were conducted to assess surface degradation.

Main Results:

• The ratio of C=O/C-H band area increased with aging time, indicating carbonyl group formation.
• A strong negative correlation was found between glossiness and carbonyl content (Spearman coefficients -0.772 and -0.782).
• Glossiness decay followed an exponential function with extended UV exposure.

Conclusions:

• The study provides a quantitative framework for assessing polyurethane coating aging.
• The findings enable prediction of long-term durability based on carbonyl group formation and glossiness reduction.
• This research aids in material selection and performance prediction for UV-exposed polyurethane applications.