Analysis of Ultraviolet-Degraded Plastic by Plastic Analyzer

Analysis of UV-Degraded Plastics by Shimadzu FTIR-Based Plastic Analyzer

Significance of the Topic

Plastic materials exposed to sunlight undergo chemical changes that compromise product performance and complicate contamination analysis. Accurate identification of degraded plastics is crucial for quality control, failure investigations, and environmental monitoring. Proprietary spectral libraries that reflect UV and thermal aging offer a solution to conventional FTIR limitations.

Objectives and Study Overview

This study demonstrates how Shimadzu’s Plastic Analyzer system enables rapid, user‐friendly qualitative analysis of UV‐degraded plastics. A blind’s plastic slat exposed to indoor sunlight was examined at three locations (interior, sheltered indoor side, and sun‐exposed window side) to assess degradation levels using specialized spectral libraries.

Methodology and Workflow

The analysis was conducted with the IR Pilot macro program, automating:

• Selection of the Plastic Analysis measurement program
• Background and sample spectral acquisition via ATR-FTIR
• Library search against UV‐ and thermal‐damaged plastics spectra
• Generation of a comprehensive report

Instrumentation Used

• Shimadzu IRSpirit Fourier Transform Infrared Spectrophotometer
• QATR-S Single-Reflection ATR Measurement Accessory
• Plastic Analyzer Method Package (UV‐ and Thermal‐Damaged Plastics Libraries)
• Super Accelerated Weathering Chamber (Iwasaki Electric Co., Ltd.) for library generation

Main Results and Discussion

Spectral overlays showed that the interior section matched unaged polypropylene (PP). The indoor side correlated with PP irradiated for 40 h, and the window side aligned with PP irradiated for 125 h. Characteristic oxidation peaks appeared at ~3400 cm⁻¹ (O–H stretch), 1710 cm⁻¹ (C=O stretch), and 1150 cm⁻¹ (C–O stretch), indicating progressive UV-induced oxidative degradation.

Benefits and Practical Applications

• Enables non‐expert users to perform reliable degradation and contaminant analyses
• Automates spectral acquisition and library matching for consistent, rapid results
• Supports quality assurance in manufacturing and service industries
• Applicable to microplastic research and environmental sample screening

Future Trends and Potential Applications

• Expansion of spectral libraries to cover additional polymers and degradation modes
• Integration of machine learning for enhanced spectral interpretation
• Real‐time, in‐line FTIR monitoring for continuous process control
• Advanced mapping of microplastic distribution in environmental matrices

Conclusion

Shimadzu’s FTIR‐based Plastic Analyzer, equipped with dedicated UV and thermal degradation libraries and automated workflows, offers a robust solution for the rapid, accurate identification of degraded plastics. It streamlines analysis, reduces operator expertise requirements, and enhances quality control and research capabilities.

References

• S. Iwasaki. Analysis of Ultraviolet-Degraded Plastic by Plastic Analyzer. Shimadzu Application Note No. A647, January 2021.