Extraction of Irganox 1076 from Polystyrene

Importance of the Topic

Supercritical fluid extraction of polymer additives such as Irganox 1076 provides a rapid and eco-friendly approach to ensure material quality by minimizing hazardous solvent use and reducing extraction time.

Objectives and Overview of the Study

This work aims to optimize SFE conditions for quantitative extraction of the antioxidant Irganox 1076 from polystyrene, demonstrating the method’s efficiency compared to traditional solvent-based techniques.

Methodology

• Sample Preparation: 1 g polystyrene ground under liquid nitrogen, mixed with 15 g Ottawa sand and packed between glass wool plugs.
• Extraction Parameters: 24 mL vessel, 7000 psi, 125 °C (valve at ~130 °C), CO₂/methanol (85:15) at 2 L/min; 15 min static, 30 min dynamic.
• Collection and Elution: Add-on 6 mL C18 SPE cartridge, elute with 5 mL methanol/methylene chloride (1:1).
• Analysis: HPLC quantification of recovered Irganox 1076.

Instrumentation

• Spe-ed™ SFE or Helix Supercritical Extraction System with modifier pump.
• Cryogenic polymer grinder for sample homogenization.
• C18 SPE cartridges for on-line extraction trapping.
• High-performance liquid chromatograph for analysis.

Key Results and Discussion

The optimized SFE method achieved quantitative recovery of Irganox 1076 with accuracy and precision comparable to Soxhlet extraction, while drastically reducing total extraction time and solvent volume.

Benefits and Practical Applications

• Substantial reduction in hazardous solvent use and disposal costs.
• Shortened extraction cycles improve laboratory throughput.
• Direct on-line trapping simplifies workflow and minimizes sample handling.
• Applicable for quality control of polymer additives in industry and research.

Future Trends and Opportunities

Advances may include automation of sample feeding, development of novel sorbent materials for on-line trapping, and integration with mass spectrometry for enhanced sensitivity and selectivity, expanding SFE applications in complex matrices.

Conclusion

Supercritical CO₂ extraction of Irganox 1076 from polystyrene combines speed, efficiency, and environmental benefits, representing a viable alternative to classic solvent-based methods for routine polymer QC.

References

Ashraf-Khorassani, M.; Boyer, D.; Levy, J. M. Quantitative Extraction of Polymer Additives from Different Polymers using On-line SFE/SFC. J. Chromatogr. Sci. 29, 517 (1991).