Characterization of Additives Typically Employed in EPDM Formulations by using FT-IR of Gaseous Pyrolyzates
http://dx.doi.org/10.4322/polimeros.2014.066 Polímeros: Ciência e Tecnologia, vol.24, n3, p.269-275, 2014
In this study, Fourier transform infrared spectroscopy (FT-IR) was employed to investigate the gaseous pyrolysis products of ethylene–propylene–diene rubber (EPDM). The objective was to evaluate the potential of FT-IR analysis of gaseous pyrolyzates (PY-G/FT-IR) for characterization of EPDM additives. Two EPDM formulations, containing additives typically employed in EPDM rubbers, were analyzed. Initially, gaseous pyrolysis products from paraffin oil, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline, tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), and 2-mercaptobenzothiazole (MBT) were characterized separately, and their main absorptions were identified. Subsequently, the gaseous pyrolysis products of raw, unvulcanized, and vulcanized EPDM formulations were analyzed. The similarities observed in the FT-IR spectra of unvulcanized and vulcanized EPDM show that the vulcanization process does not interfere with the pyrolysis products. The identification of the functional groups of the studied additives was possible in both unvulcanized and vulcanized EPDM samples, without solvent extraction. Results also demonstrate that the PY-G/FT-IR technique can identify additives containing sulfur in concentrations as low as 1.4 phr (1.26%) in both unvulcanized and vulcanized EPDM. However, the method showed some limitation due to overlapping and to similarities of TMTM and TMTD PY-G/FT-IR spectra, which could not be distinguished from each other. The PY-G/FT-IR technique is a faster and cheaper alternative to the sophisticated techniques usually applied to detection of additives in rubbers.
EPDM, gaseous pyrolyzates, additives, characterization, FT-IR
1. Raemaekers, K.G.H. & Bart, J.C.J. Thermoch. Acta, 295, p.1 (1997).
2. Çavdar, S.; Özdemir, T. & Usanmaz, A. - Plast., Rubber Compos., 39, p.277 (2010).
3. Fishbein, L. - Scand J Work Environ Health, 9, p. 7 (1983).
4. Buchberger, W.; Stftinger, M. – Adv. Polym. Sci., 248, p.39 (2012)
5. Wampler, T.P. - “Applied Pyrolysis Handbook”, Boca Raton (2007).
6. Choi, S. & Kim, Y. – Polym. Test., 30, p.509 (2011).
7. Hiltz, J. A. – J. Appl. Pyrolysis, 55, p. 135 (2000).
8. Wang, F.C.; Buzanowski, W.C. - J. Chromatogr. A, 891, p.313 (2000).
9. Jansson, K. D.; Zawodny, C. P. & Wampler, T. P. – J. Appl. Pyrolysis, 79, p.353 (2007).
10. Kusch, P. – Spectroscopy, july/2012, p.8, (2012).
11. Sobeih, K.L.; Baron, M. & Gonzales-Rodriguez, J. – J. Chromatogr. A, 1186, p.51 (2008).
12. Kim, S.W.; Heo, G.S. & Lee, G.H. – Anal. Sci., 13, p.257 (1997).
13. Smith, P. B. et al. – Anal. Chem., 71, p.61 (1999).
14. Blazsó, M. – J. Anal. Appl. Pyrolysis, 39, p.1 (1997).
15. Alekseeva, K. V. – J. Anal. Appl. Pyrolysis, 2, p.19 (1980).
16. Jiménez, A. & Ruseckaite, R. A. - Encyclopedia of Chromatography, chapter 298, p.1396 (2005).
17. Bart, J. C. J. – “Additives in Polymers: Industrial Analysis and Applications”, John Wiley & Sons, Chichester (2005).
18. Nunes, S. P. et al. – IEE Transactions on Electrical Insulation, 24, p.99 (1989).
19. Matheson, M. J.; Wampler, T. P. & Simonsick Jr., W.J. – J. Anal. Appl. Pyrolysis, 29, p.129 (1994).
20. Fernández-Berridi, M. J. et al. – Thermochim. Acta, 444, p.65 (2006).
21. Sanches, N. B. et al. – Polímeros, 16, nº 3, p.211 (2006).
22. American Society for Testing and Materials – ASTM. – “D1566: Standard Terminology Relating to Rubber (2011).
23. American Society for Testing and Materials – ASTM. – “D3568: Standard Test Methods for Rubber – Evaluation of EPDM (Ethylene Propylene Diene Terpolymers) Including Mixtures With Oil”, Philadelphia (2009).
24. Socrates, G. – “Infrared and Raman Characteristic Group Frequencies: Tables and Charts”, Wiley & Sons, Chichester (2001).
25. Welti, D. & Stephany, R. – Appl. Spectrosc., 22, p.678 (1968).
26. Young, P. R. – “Practical Spectroscopy: The Rapid Interpretation of Spectral Data”, Thomson Learning, Pacific Groove (2000).
27. Silverstein, R.M.; Webster, F.X. & Kiemle, D.J. – “Spectrometric identification of organic compounds”, John Wiley & Sons, New York (2005).
28. BIO-RAD/SADTLER Reference Database - 20 MAR 2013
29. Smejkal, F. et al – Die Angewandte Makromolekulare Chimie, 88 p.135 (1980).
30. NIST Standard Reference Database 69: NIST Chemistry WebBook – 3 MAR 2013
31. Nieuwenhuizen, P. J. et al. - Rubber Chem. Technol., 70, p.368 (1997).
32. Contini, G. et al. – J. Phys. Chem. A, 106, p.2833 (2002).
33. Wu, F.-L. et al. - Curr. Org. Chem., 16, p.1555 (2012).
34. Mohamed, T. A. et al. – J. Mol. Struct.: THEOCHEM, 868, p.27 (2008).