Analysis of Ultraviolet-Degraded Plastic by Plastic Analyzer

Importance of the Topic

Plastic contaminants on production lines can lead to product defects and regulatory issues. Over time, exposure to ultraviolet radiation and heat alters the chemical structure of polymers, making their identification by standard spectral libraries difficult. A reliable method for assessing degradation in plastics supports quality control, materials research, and environmental monitoring.

Objectives and Overview of the Study

This application note demonstrates the use of a dedicated FTIR-based Plastic Analyzer system to perform rapid qualitative analysis of UV-degraded plastics. A real-world sample—a window blind fragment exposed to indoor sunlight—serves to illustrate the workflow from measurement to degradation assessment using proprietary spectral libraries.

Methodology and Instrumentation

The study employed a Fourier transform infrared spectrometer equipped with an attenuated total reflection accessory and a specialized software package. The key steps included background measurement, sample measurement, and automated spectrum search against UV- and thermal-degraded polymer libraries using a guided macro program.

Instrumentation Used

• Fourier Transform Infrared Spectrophotometer with ATR accessory
• UV-Degraded Plastics Library containing spectra of 14 polymers exposed to accelerated UV weathering
• Thermal-Degraded Plastics Library with spectra of 13 polymers before and after heating to 200–400 °C
• Dedicated macro program for setting optimal parameters, performing measurements, and generating reports

Main Results and Discussion

The interior of the blind sample was identified as unaged polypropylene. The indoor side matched a specimen irradiated for 40 hours, while the window side corresponded to a 125-hour UV exposure. Progressive oxidation introduced absorbance bands near 3400 cm−1 (O–H stretching), 1710 cm−1 (C=O stretching), and 1150 cm−1 (C–O stretching), indicating increasing degradation with prolonged UV exposure.

Benefits and Practical Applications

• Fast, user-friendly qualitative analysis of aged plastics even by non-expert operators
• Automated workflow from measurement setup to report generation
• High accuracy in identifying both polymer type and degradation state
• Applicability to contaminant screening, microplastic research, and failure analysis

Future Trends and Opportunities

Expanding spectral libraries to cover additional polymer types and degradation mechanisms will enhance identification capabilities. Integration with microscopy and imaging FTIR can enable spatially resolved degradation mapping. Online and in-line monitoring solutions may emerge for real-time quality control in manufacturing environments.

Conclusion

The FTIR-based Plastic Analyzer with proprietary UV and thermal degradation libraries enables rapid, accurate qualitative analysis of aged polymer samples. Its automated measurement and reporting streamline workflows, supporting diverse applications from routine QC to advanced materials research.

Reference

No formal literature references were provided in the original application note.