Acetaldehyde Generation in Processing PET by Means of Hot Runner Systems

Abstract:

Polyethylene terephthalate (PET) is a polyester widely used as packaging material in drink-bottling application. PET is rather sensitive to heat and oxidation and during processing it may undergo degradation reaction with generation of acetaldehyde. In this work the generation of acetaldehyde in a hot runner system has been measured. A special test apparatus was developed to separate the contributions due to the action of the extruder screw from those due to the melt residence at high temperature. Results showed that the acetaldehyde content non-linearly increases with temperature and residence time. A model has been proposed to provide for the generation of acetaldehyde as a function of temperature and residence time regardless of the geometry and other specific conditions of the process.

• Periodical: Key Engineering Materials (Volumes 611-612)
• Pages: 922-927
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.611-612.922
• Online since: May 2014
• Authors: Giovanni Lucchetta*, Serafina Chirico
• Keywords: Acetaldehyde, Extrusion, Hot-Runners, Polyethylene Terephthalate

References

[1] Dzieciol, M., Trzeszczynski, J., 1998. Studies of temperature influence on volatile thermal degradation products of poly(ethylene terephthalate), Journal of Applied Polymer Science, vol. 69/12, pp.2377-2381.

DOI: 10.1002/(sici)1097-4628(19980919)69:12<2377::aid-app9>3.0.co;2-5

[2] Villain, F., Coudane, J., Vert, M., 1995. Thermal degradation of polyethylene terephthalate: study of polymer stabilization, Polymer degradation and stability, vol. 49/3, pp.393-397.

DOI: 10.1016/0141-3910(95)00121-2

[3] Mutsuga, M., Kawamura, Y., Sugita-Konishi, Y., Hara-Kudo, Y., Takatori, K., Tanamoto, K., 2006. Migration of formaldehyde and acetaldehyde into mineral water in polyethylene terephthalate (PET) bottles, Food Additives and Contaminants, vol. 23/2, pp.212-218.

DOI: 10.1080/02652030500398361

[4] Zimmerman, H., Kim, N.T., 1980. Investigations on thermal and hydrolytic degradation of poly(ethylene terephthalate), Polymer Engineering and Science, vol. 20/10, pp.680-683.

DOI: 10.1002/pen.760201008

[5] Ewender, J., Franz, R., Mauer, A., Welle, F., 2003. Determination of the migration of acetaldehyde from PET bottles into non-carbonated and carbonated mineral water, Deutsche Lebensmittel Rundschau, vol. 99/6, pp.215-221.

[6] Paci, M., La Mantia, F.P., 1998. Competition between degradation and chain extension during processing of reclaimed poly(ethylene terephthalate), Polymer Degradation and Stability, vol. 61/3, pp.417-420.

DOI: 10.1016/s0141-3910(97)00227-9

[7] Marshall, I., Todd, A., 1953. The thermal degradation of polyethylene terephthalate, Transactions of the Faraday Society, vol. 49, pp.67-78.

DOI: 10.1039/tf9534900067

[8] Goodings, E.P., 1961. Thermal degradation of poly(ethylene terephthalate), Soc Chem Ind (London) Monograph 13: 211.

[9] Jabarin, S.A., Lofgren, A.A., 1984. Thermal Stability of Polyethylene Terephthalate, Polymer engineering and Science, vol. 24/13, pp.1056-1063.

DOI: 10.1002/pen.760241311

[10] Khemani, K.C., 2000. A novel approach for studying the thermal degradation, and for estimating the rate of acetaldehyde generation by the chain scission mechanism in ethylene glycol based polyesters and copolyesters, Polymer Degradation and Stability, vol. 67/1, p.91.

DOI: 10.1016/s0141-3910(99)00097-x

[11] Shukla, S.R., Lofgren, E.A., Jabarin, S.A., 2005. Effects of injection-molding processing parameters on acetaldehyde generation and degradation of poly(ethylene terephthalate), Polymer International, vol. 54/6, p.946–955.

DOI: 10.1002/pi.1794