Analysis of Residual Monomers in UV Curable Resin

Importance of the topic

Residual monomers in UV-curable resins can affect product performance, pose safety risks, and complicate regulatory compliance. Monitoring these residual compounds is essential for ensuring material quality and process reliability.

Objectives and overview of the study

This application note outlines a headspace GC-MS method for detecting and quantifying 1,4-butanediol and 4-hydroxybutyl acrylate in UV-curable resins. The goal is to achieve clear separation, high sensitivity, and robust reproducibility under defined conditions.

Methodology and Instrumentation

• Instrumentation: Shimadzu GCMS-QP2020 NX with HS-20 headspace sampler
• GC Conditions:
  • Column: SH-PolarWax (30 m × 0.32 mm I.D., 0.5 µm)
  • Oven program: 100 °C initial hold; ramp at 10 °C/min to 240 °C; hold 3 min
  • Carrier gas: helium at constant linear velocity (50 cm/min)
• Headspace Parameters:
  • Equilibration: 210 °C for 30 min
  • Pressurization: 150 kPa for 0.5 min
  • Injection: split mode (100:1); loop injection; needle flush 2 min
• MS Settings:
  • Ionization: EI, scan m/z 35-500
  • Ion source: 200 °C; interface: 250 °C

Main results and discussion

The total ion chromatogram achieved baseline separation of the target monomers. 1,4-Butanediol and 4-hydroxybutyl acrylate were identified by characteristic mass fragments (m/z 71). The method showed excellent repeatability across multiple injections and minimal interference from the resin matrix, enabling accurate quantification at low levels.

Benefits and practical applications

• Ensures quality control in UV-resin manufacturing processes
• Supports compliance with safety and environmental regulations
• Facilitates process optimization by tracking residual monomer content

Future trends and potential applications

• Automated sample preparation for high-throughput screening
• Application to a broader range of reactive monomers and additives
• Integration of machine learning for enhanced data interpretation
• Development of portable GC-MS systems for on-site analysis

Conclusion

The described HS-GC-MS method using Shimadzu GCMS-QP2020 NX and HS-20 sampler with SH-PolarWax column provides a sensitive, reproducible, and straightforward approach for monitoring residual monomers in UV-curable resins, ensuring product quality and safety.

References

• Application News 01-00174 (JP), Shimadzu Corporation, First Edition: September 2022