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Initiator Systems for Unsaturated Polyester Resins

  • V. R. Kamath
  • R. B. Gallagher
Chapter
Part of the The Development Series book series (POLS, volume 30)

Summary

The basic principles of free radical initiators, their important parameters and new developments as they relate to the selection of effective initiator systems for curing unsaturated polyester resins are reviewed.

Peroxide and azo type initiators continue to be the most popular initiators for the fibre reinforced plastics (FRP) industry. Certain peroxides can be decomposed by specific promoters to provide good cures at ambient temperatures. The mechanism of activation and particularly the detrimental effects of excess promoter are described. The results of studies relating the structure of ketone peroxides to their reactivity are reviewed.

The kinetics of thermal decomposition of initiators are related to important processing parameters such as shelf-life, rate of cure and temperature of cure. For easy reference, specific initiators used for curing in the 100°–160°C temperature range are tabulated along with their 10 h t1/2 temperatures. The advantages of peroxyketals over popular peroxyesters, and their sensitivity to acidic fillers are discussed. The advantages of peroxide blends in terms of fast cure systems and especially the long shelf-life of blends containing unique azo compounds are described. Results of studies directed towards the reduction of residual styrene in cured resin are reviewed.

In addition to azo and peroxide compounds, other sources of free radicals are reviewed including novel carbon-carbon initiator and photoinitiator systems based on both UV and visible light.

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References

  1. 1.
    Pryor, W. A. Free Radicals, 1966, McGraw-Hill Inc., New York.Google Scholar
  2. 2.
    Gallagher, R. B. and Kamath, V. R. Plastics Design and Processing, 1978, 18(7), 38.Google Scholar
  3. 3.
    Sheppard, C. S. and Kamath, V. R. Polym. Eng. Sci., 1979, 19, 597.CrossRefGoogle Scholar
  4. 4.
    Cassoni, J. P., Harpell, G. A., Wang, P. C. and Zupa, A. H. 32nd SPI Reinforced Plastics/Composites Conf., 1977, Paper 3-E.Google Scholar
  5. 5.
    Thomas, A., Jacyszyn, O., Schmitt, W. and Kolczynski, J. 32nd SPI Reinforced Plastics/Composites Conf., 1977, Paper 3-B.Google Scholar
  6. 6.
    Maxstadt, A. Kunststoffe, 1979, 69, 266.Google Scholar
  7. 7.
    Thomas, A., Roskott, L., Groenendaal, A. A. M. and Kolczynski, J. R. 33rd SPI Reinforced Plastics/Composites Conf., 1978, paper 5-E.Google Scholar
  8. 8.
    Bukata, S. W., Zabrocki, L. L., Mclaughlin, M. F., Kolczynski, J. R. and Mageli, O. L. Ind. Eng. Chem. Prod. Res. Develop., 1964, 3, 261.CrossRefGoogle Scholar
  9. 9.
    US Patent No. 4,032,596 issued to Air Products and Chemicals Inc., 28 June, 1977.Google Scholar
  10. 10.
    Cassoni, J. P., Gallagher, R. B. and Kamath, V. R. 34th SPI Reinforced Plastics/Conposites Conf., 1979, Paper 14-F.Google Scholar
  11. 11.
    Ampthor, F. J. Plastics World, 1978, 36(5), 48.Google Scholar
  12. 12.
    Kamens, E. R., Gallagher, R. B. and Kamath, V. R. 34th SPI Reinforced Plastics/Composites Conf., 1979, Paper 16-B.Google Scholar
  13. 13.
    Roskott, L. and Groenendaal, A. A. M. 33rd SPI Reinforced Plastics/Composites Conf., 1978, Paper 5-B.Google Scholar
  14. 14.
    Izzard, K. J. and Newton, G. P. 33rd SPI Reinforced Plastics/Composites Conf., 1978, Paper 5-C.Google Scholar
  15. 15.
    Varco, P. 30th SPI Reinforced Plastics/Composites Conf., 1975, Paper 6-C.Google Scholar
  16. 16.
    Shapras, P. and Clover, G. C. Anal. Chem., 1964, 36, 2282.CrossRefGoogle Scholar
  17. 17.
    German Patent No. 2,815,924 issued to Akzo G.m.b.H., 19 April, 1977.Google Scholar
  18. 18.
    Braun, D. and Quella, F. Kunstoffe, 1979, 69, 100.Google Scholar
  19. 19.
    Delzenne, G. A. Makromol. Chem., 1979, Suppl. 2, 169.Google Scholar
  20. 20.
    Dixon, B. G., Longenecker, D. M. and Greth, G. G. 32nd SPI Reinforced Plastics/Composites Conf., 1977, Paper 5-D.Google Scholar
  21. 21.
    Kolek, R. L. and Hammill, J. L. Plastics Compounding, 1979, 2(6), 52.Google Scholar

Copyright information

© Applied Science Publishers Ltd 1980

Authors and Affiliations

  • V. R. Kamath
    • 1
  • R. B. Gallagher
    • 1
  1. 1.Pennwalt CorporationBuffaloUSA

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