Skip to main content
SpringerLink
Log in

Styrenics materials and cyclopentane: problems and perspectives

  • Published:
Journal of Materials Science Aims and scope Submit manuscript

Abstract

The use of chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC) has been greatly limited in recent years because of their high ozone depletion potential (ODP) (Montreal protocol). The manufacturers of refrigerators have tried various new blowing agents for polyurethane (PU) foams used as insulating panels, and currently the chosen organic compound in Europe seems to be cyclopentane (CP), due to its acceptable insulating power and null ODP and toxicity. Unfortunately the interaction of CP with high impact polystyrene (HIPS) panels of the refrigerators produces blisters and can possibly induce environmental stress cracking (ESC). The aim of this work is, then, to explain the growth of blisters with a theoretical calculation and also to investigate the mechanical behaviour of HIPS in contact with gaseous and liquid CP, in comparison with usually used Freon® 11 (F11).

By means of the group contribution one can calculate with the Flory-Huggins equation an isothermal adsorption curve for the polystyrene (PS) matrix/organic system and with the Chow equation calculate the lowering of T g. From the calculation it is evident that the lower CP vapour pressure causes a considerable absorption, and this is simultaneous to the lesser CP amount needed to reach a 23 °C T g for the PS matrix: it is then possible to state that the blisters form from a sort of micro blow-moulding, induced in the plasticized PS by the thermal treatments that are introduced in the refrigerator production cycle. The use of small amounts of acrylonitrile (AN) in the PS matrix may be sufficient to avoid this inconvenience, as it has been confirmed by lab and industrial experiences.

From a mechanical point of view two experimental set-ups were designed in order to evaluate the ESC resistance in gaseous and liquid environment: for the first case slow crack propagation (SCP) experiments were performed in controlled atmospheres on compact tension (CT) specimens, while in the second case the essential work of fracture (EWF) technique was applied to double edge notch (DEN) specimens fully immersed in the considered liquids at different temperatures. In the first case it can be immediately concluded that the ESC produced in the presence of the same pressure of the two different agents (CP and F11) is very different, the CP one being much more aggressive than the F11. However, if the data are plotted versus the thermodynamic activity, there is no meaningful difference between CP and F11, suggesting that this parameter controls the ESC in gaseous environment for the considered blowing agents. In the case of ESC in the presence of a liquid, that could have a practical relevance in refrigerators if condensation phenomena take place, one observes that ordinary HIPS becomes rapidly brittle, while an AN modified HIPS maintains an appreciable ductility also in the presence of the liquid solvents.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. M. D. LEMONICK, Time Int. 45 (1994) 61.

    Google Scholar 

  2. R. A. BUBECK, C. B. ARENDS, E. L. HALL and J. B. Vander SANDE, Polym. Engng. Sci. 21 (1981) 624.

    Article  CAS  Google Scholar 

  3. S. V. HOA, ibid. 20 (1980) 1157.

    Article  CAS  Google Scholar 

  4. A. SAVADORI, D. BACCI and C. MAREGA, Polym. Test. 7 (1987) 59.

    Article  CAS  Google Scholar 

  5. M. A. VUL'F, V. S. POLONSKII, T. G. SHLYAKHOVA and Y. V. NIKITIN, Int. Polym. Sci. Tech. 15 (1988) T/62.

    Google Scholar 

  6. G. CIGNA, M. ROSSI, Montedipe Internal Report 68/82 (1982).

  7. Italian Patent 19 220 (1980).

  8. Fed. Rep. Germ. Patent 2946 761 (1979).

  9. Fed. Rep. Germ. Patent 2951 117 (1979).

  10. Arbeits Gemelnschaft KalteIndustrie, Prüf. Thermoplast. Kunst. 31 (1970).

  11. C. MAREGA, Zanussi Elettrodomestici SpA, private communication.

  12. P. J. FLORY, “Principles of Polymer Chemistry” (Cornell University Press, Ithaca, NY, 1953).

    Google Scholar 

  13. A. F. M. BARTON, “CRC handbook of solubility parameters and other cohesion parameters” (CRC Press Inc., Boca Raton, Florida, 1983).

    Google Scholar 

  14. Y. W. MAI, J. Mater. Sci. 21 (1986) 904.

    Article  CAS  Google Scholar 

  15. T. S. CHOW, Macromolecules 13 (1980) 362.

    Article  CAS  Google Scholar 

  16. G. BROWN and A. J. KOVACS, in Proc. Conf. on Physics of Non-Crystalline Solids, 1965, edited by J. A. PRINS (North-Holland, Amsterdam, 1965) p. 303.

    Google Scholar 

  17. G. F. SMITHS and J. A. THOEN, J. Cellular Plastics 29 (1993) 57.

    Article  Google Scholar 

  18. J. G. WILLIAMS and M. J. CAWOOD, Polym. Test. 9 (1990) 15.

    Article  CAS  Google Scholar 

  19. European group on fracture, EGF Newslett. 1 (1986/1987).

  20. C. MAESTRINI, L. MONTI and H. H. KAUSCH, Polymer (accepted).

  21. P. C. PARIS, in Proc. 10th Sagamore Conf., 1964 (Syracuse University Press, Syracuse, NY, 1964).

    Google Scholar 

  22. R. W. HERTZBERG and J. A. MANSON, “Fatigue of Engineering Plastics” (Academic Press, London, 1980).

    Google Scholar 

  23. R. W. HERTZBERG and J. A. MANSON, in “Encyclopaedia of Polymer Science and Engineering”, 1985 (John Wiley and Sons, New York, 1985) vol. 10.

    Google Scholar 

  24. B. COTTERELL and J. K. REDDEL, Int. J. Fract. 13 (1977) 267.

    CAS  Google Scholar 

  25. K. B. BROBERG, ibid. 4 (1968) 11.

    Article  Google Scholar 

  26. Y. W. MAI and B. COTTERELL, ibid. 32 (1986) 105.

    Article  CAS  Google Scholar 

  27. Y. W. MAI, B. COTTERELL, R. HORLYCK and G. VIGNA, Polym. Engng. Sci. 27 (1987) 804.

    Article  CAS  Google Scholar 

  28. Y. W. MAI and P. POWELL, J. Polym. Sci. B: Polym. Phys. 29 (1991) 785.

    Article  CAS  Google Scholar 

  29. C. A. PATON and S. HASHEMI, J. Mater. Sci. 27 (1992) 2279.

    Article  CAS  Google Scholar 

  30. J. G. WILLIAMS, “Fracture Mechanics of Polymers” (Ellis Horwood, Chichester, 1984).

    Google Scholar 

  31. C. MAESTRINI, M. MERLOTTI, M. VIGHI and E. MALAGUTI, J. Mater. Sci. 27 (1992) 5994.

    Article  CAS  Google Scholar 

  32. S. ANZALDI, L. BONIFACI, E. MALAGUTI, M. VIGHI and G. P. RAVANETTI, J. Mater. Sci. Lett. 13 (1994) 1555.

    Article  CAS  Google Scholar 

  33. K. KATO, Polym. Engng. Sci. 7 (1967) 38.

    Article  CAS  Google Scholar 

  34. E. J. KRAMER, in “Developments in Polymer Fracture”, edited by E. H. ANDREW (Applied Science, London, 1979).

    Google Scholar 

  35. H. G. OLF and A. PETERLIN, J. Polym. Sci.: Polym. Phys. 12 (1974) 2209.

    CAS  Google Scholar 

  36. N. BROWN, J. Macromol. Sci.-Phys., B19 (1981) 387.

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Enichem Research Centre, Via Taliercio 14, 46100, Mantova, Italy

    C. Maestrini, A. Callaioli, M. Rossi & R. Bertani

Authors
  1. C. Maestrini
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. Callaioli
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. M. Rossi
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. R. Bertani
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Maestrini, C., Callaioli, A., Rossi, M. et al. Styrenics materials and cyclopentane: problems and perspectives. JOURNAL OF MATERIALS SCIENCE 31, 3747–3761 (1996). https://doi.org/10.1007/BF00352790

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00352790

Keywords

Search

Navigation