Composition Analysis of Adhesives Using Double-Shot Pyrolyzer and Peripheral Devices Part 1: EGA and Library Search with EGA-MS LIB

Significance of the Topic

The composition analysis of adhesives is vital for ensuring product performance, quality control and failure analysis across diverse industries. Rapid identification of both low-molecular-weight additives and polymer constituents enables more efficient development, regulatory compliance and troubleshooting.

Objectives and Overview of the Study

This application note demonstrates the use of Double-Shot Pyrolyzer® coupled with evolved gas analysis (EGA) and mass spectrometry for primary screening of an adhesive sample with unknown composition. The study aims to distinguish low-boiling compounds, side-chain cleavage products and main polymer backbones through thermal profiling and library spectral matching.

Methodology

Evolved gas analysis was performed by heating the sample from 100 °C to 600 °C at a rate of 20 °C/min under helium (50 kPa). Thermal regions A, B and C were defined based on the EGA curve. Mass spectra were averaged for each region after subtracting background signals, then searched against the Wiley275 MS library for compound identification.

Used Instrumentation

• Double-Shot Pyrolyzer with pyrolysis temperature ramp of 100 °C–600 °C (20 °C/min); capillary tube 0.15 mm i.d., 2.5 m (UADTM-2.5N)
• Carrier gas: helium at 50 kPa; split ratio approx. 1/50
• Gas chromatograph oven temperature: 300 °C; pyrolyzer-GC interface: 320 °C
• Mass spectrometer detector scanning m/z 29–400 at 0.1 scan/s
• Sample amount: ~1.0 mg; injection temperature: 320 °C

Main Results and Discussion

• Region A exhibited a low-temperature peak identified as a volatile compound by library match (structure shown in Fig. A).
• Region B spectrum was dominated by acetic acid, indicating side-chain scission of vinyl acetate units.
• Region C library search returned high matches to vinyl polymers: poly(vinyl chloride) (score 62), poly(vinyl acetate) (score 60) and poly(vinyl alcohol) (score 43).

The detection of acetic acid confirms the presence of vinyl acetate in the adhesive polymer. The combined EGA profile and library search prove highly effective for initial compositional assessment of unknown samples.

Benefits and Practical Applications

• Rapid, non-targeted screening of adhesive formulations and polymer materials.
• Supports quality control in adhesive manufacturing and polymer processing.
• Assists failure analysis by revealing additives and degradation products.

Future Trends and Potential Applications

Advancements may include coupling EGA-GC/MS for detailed separation of evolved components, expansion and curation of spectral libraries, integration of chemometric and machine learning approaches for automated interpretation, and application to complex polymer blends, composites and environmental samples.

Conclusion

The Double-Shot Pyrolyzer® EGA-MS library search method provides an efficient and informative primary screening tool for adhesive composition analysis. By combining thermal profiling with mass spectral matching, it enables rapid identification of both additives and polymer backbones, offering significant benefits for research, quality assurance and industrial analytics.