Sustainability: Challenges in Polymer characterization and applications of Pyrolysis-GC/MS

Significance of the Topic

The combined use of pyrolysis-GC/MS, evolved gas analysis (EGA-MS), thermal desorption (TD-GC/MS) and heart-cut EGA-GC/MS provides a powerful toolkit for rapid and detailed characterization of polymers, additives and degradation products. This approach addresses critical needs in materials development, quality control, failure analysis and environmental monitoring, including microplastics research and sustainability studies.

Objectives and Overview

This whitepaper introduces a multifunctional pyrolyzer platform paired with metal capillary columns and advanced accessories to:

• Detail the principles and configurations of pyrolysis-GC/MS methods.
• Demonstrate applications in polymer discoloration, bio-plastic identification, recycled material failure and microplastic analysis.
• Quantify key additives such as stabilizers, antioxidants and lubricants in commercial plastics.
• Provide insights into thermal behavior, degradation pathways and environmental fate of polymeric materials.

Methodology and Instrumentation

Instrumentation:

• Multi-Shot Pyrolyzer EGA/PY-3030D with thermal desorption and single-shot pyrolysis modes
• Ultra ALLOY® metal capillary columns for high-temperature separation
• Tandem micro-reactor Rx-3050TR for on-line catalytic evaluation
• Cryogenic Mill IQ MILL-2070 for sample homogenization
• GC/MS system (split/splitless inlet, tandem valves, cryo-trap module)

Analytical methods:

• Evolved Gas Analysis-MS (EGA-MS) to profile thermal events and detect volatiles (HCl, solvents, additives).
• Single-Shot and Double-Shot pyrolysis-GC/MS for comprehensive fingerprinting of polymers and additives.
• Thermal Desorption-GC/MS (TD-GC/MS) focused on low-molecular volatiles and surface additives.
• Heart-Cut EGA-GC/MS for targeted separation of defined temperature zones.

Main Results and Discussion

1. Yellowing of PVC Foils

• EGA-MS revealed distinct thermal zones and higher HCl release from discolored surfaces, indicating stabilizer depletion.
• Py-GC/MS identified polyene pyrolyzates and degradation of tin-based stabilizers on yellow side versus white side.
• Metallic soaps (Ca-Zn) and long-chain alcohols were differentially detected, linking additive distribution to color change.

2. Analysis of Bio-Based and Conventional Plastic Bags

• EGA-MS and Py-GC/MS distinguished polymer matrices: PE, PP, PBSA, PLA and PBAT in bio-bags.
• TD-GC/MS quantified erucamide (up to 705 ppm) and Irgafos 168 (95–450 ppm) across samples using standard addition.
• Additive profiles correlated with material performance and environmental compatibility.

3. Failure Analysis of Recycled ABS Brush Bases

• Py-GC/MS and SEM-EDX showed similar polymer composition in good and defective products.
• TD-GC/MS quantification revealed severe depletion of antioxidants (AO-40, Irganox 1076) in recycled material, leading to cracking during bristle implantation.

4. Microplastics in Sediments

• Micro-furnace pyrolysis-GC/MS with cryo-trap allowed fast screening of MPs (1 µm–5 mm).
• F-Search MPs software and library of 12 polymers enabled automated identification and quantification in coastal and offshore sediments.
• Results showed predominant PE and PS fractions with minor PP, PMMA, PET and nylon contributions.

Benefits and Practical Applications

• Rapid material identification and additive quantification for quality assurance and regulatory compliance.
• Failure diagnostics in recycled and consumer plastics to guide reformulation and reuse strategies.
• Environmental monitoring of microplastics in water and sediment matrices with high sensitivity and throughput.
• Support for R&D in polymer formulation, catalytic degradation and sustainability initiatives.

Future Trends and Potential Uses

• Expansion of polymer and additive libraries driving higher confidence in automatic spectral matching.
• Integration of machine learning for predictive thermal behavior and degradation pathways.
• Enhanced miniaturization and field-deployable pyrolysis-GC/MS systems for on-site environmental screening.
• Development of nanoplastic analysis protocols and coupling with high-resolution mass spectrometry.

Conclusion

The multifunctional pyrolyzer combined with GC/MS and dedicated software tools provides a versatile and reliable platform for comprehensive polymer analysis. Its applications span from fundamental thermal profiling to real-world case studies in product quality, environmental science and circular economy, addressing current and emerging challenges in analytical chemistry.

Reference

• X. Zhao et al., Environ. Sci. Technol., 54 (2020) 4712.
• K. Matsui et al., J. Anal. Appl. Pyrolysis, 149 (2020) 104834.
• K. Tei et al., J. Anal. Appl. Pyrolysis, 168 (2022) 105707.