Rapid evaluation of ethylene vinyl acetate degradation using online UV irradiation Py-GC/MS

Importance of the Topic

The analysis of photo-, thermal-, and oxidative degradation in polymers such as EVA is critical for predicting material lifespan and performance under environmental stressors.

Objectives and Study Overview

This technical note describes the rapid assessment of EVA resin degradation under UV irradiation at 60 °C using an integrated UV/Py-GC/MS system to monitor volatile byproducts and changes in polymer thermal behavior.

Methodology

Powdered EVA samples were exposed to UV light (280–450 nm, 700 mW/cm²) in air at 60 °C for defined intervals. Volatile compounds generated during irradiation were cryo-trapped with liquid nitrogen, then released for GC/MS analysis. The residual polymer underwent EGA-MS to evaluate alterations in thermal degradation profiles.

Instrumentation

• UV irradiator UV-1047Xe with xenon lamp (280–450 nm, 700 mW/cm²)
• Multi‐Shot Pyrolyzer EGA/PY-3030D furnace at 60 °C
• GC/MS system with Ultra ALLOY+-1 column (dimethylpolysiloxane, 30 m × 0.25 mm i.d., 0.5 µm film)
• Liquid N₂ cryo‐trap and MS detector (3 sec/scan)

Key Findings and Discussion

Major volatile degradation products identified after UV exposure include acetic acid, formaldehyde, acetaldehyde, and acetone. EGA thermograms showed a 13 °C decrease in the main degradation peak apex after 20 hr irradiation and a broader degradation profile. The onset temperature for desorption/degradation shifted downward from 270 °C to 110 °C, indicating substantial main‐chain scission.

Benefits and Practical Applications

The online UV/Py-GC/MS approach enables rapid, simultaneous evaluation of volatile emissions and polymer backbone alterations, facilitating accelerated weathering tests, quality control, and material development.

Future Trends and Applications

Integration with advanced MS detectors and real‐time data analysis software may further enhance sensitivity and throughput. Extension to other polymer systems and coupling with mechanical testing could provide holistic degradation assessments.

Conclusion

The developed UV/Py-GC/MS method provides an efficient means to characterize photo‐oxidative degradation in EVA, capturing both volatile byproduct formation and changes in thermal stability, supporting accelerated aging studies.

References

• C. Watanabe et al.; Polymer Degradation and Stability, 94 (2009) 1467-1472
• Technical note PYA5-004E