Journal of Materials Engineering and Performance

, Volume 11, Issue 6, pp 659–666 | Cite as

Tensile strength of radio frequency cold plasma treated PET fibers—Part I: Influence of environment and treatment time

  • M. O. H. Cioffi
  • H. J. C. Voorwald
  • V. Ambrogi
  • T. Monetta
  • F. Bellucci
  • L. Nicolais


This article reports on a series of experiments with polyethylene terepthalate (PET) treated in a radio frequency plasma reactor using argon and oxygen as a gas fuel, for treatment times equal to 5 s, 20 s, 30 s, and 100 s. The mechanical strength modification of PET fibers, evaluated by tensile tests on monofilaments, showed that oxygen and argon plasma treatment resulted in a decrease in the average tensile strength compared with the untreated fibers. This reduction in tensile strength is more significant for argon plasma and is very sensitive to the treatment time for oxygen plasma. Scanning electron microscopy (SEM) used to analyze the effects of cold plasma treatment of fiber surfaces indicates differences in roughness profiles depending on the type of treatments, which were associated with variations in mechanical strength. Differences in the roughness profile, surveyed through an image analysis method, provided the distance of roughness interval, Dri. This parameter represents the number of peaks contained in a unit length and was introduced to correlate fiber surface condition, before and after cold plasma treatments, and average tensile strength. Statistical analysis of experimental data, using Weibull cumulative distribution and linear representation, was performed to explain influences of treatment time and environmental effects on mechanical properties. The shape parameter, α, and density parameter, β, from the Weibull distribution function were used to indicate the experimental data range and to confirm the mechanical performance obtained experimentally.


argon oxygen PET fiber plasma treatment statistical analysis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M.O.H. Cioffi: Análise da Estrutura e do Comportamento Mecânico de Compósitos Fibra/Resina Tratados a Plasma, Ph.D. Thesis, UNESP, Dept. of Materials and Technology, Guaratinguetá/SP, 12416410, Brazil, 2001 (in Portugese).Google Scholar
  2. 2.
    S. Weidner, G. Kühn, R. Decker, D. Roessner, and J. Friedrich: “Influence of Plasma Treatment on the Molar Mass of Poly(Ethylene Terephtalate) Investigate by Different Chromatographic and Spectroscopy Methods,” J. Polym. Sci.: Part A: Polym. Chem., 1998, 36, p. 1639.CrossRefGoogle Scholar
  3. 3.
    S.A.C. Gould, D.A. Schiraldi, and M.L. Occelli: “Analysis of Poly-(Ethylene Terephthalate) (PET) Films by Atomic Force Microscopy,” J. Appl. Polym. Sci., 1998, 67(7) pp. 1237–43.CrossRefGoogle Scholar
  4. 4.
    P.J. Herrera-Franco and L.T. Drzal: “Comparison of Methods for the Measurement,” Composites, 1992, 23(1), pp. 2–27.CrossRefGoogle Scholar
  5. 5.
    A. Teishev and A. Maron: “The Effect of Transcrystallinity on the Transverse Mechanical Properties of Single-Polymer Polyethylene Composites,” J. Appl. Polym. Sci., 1995, 56, pp. 959–66.CrossRefGoogle Scholar
  6. 6.
    K.A. Kodokian and A.J. Kinloch: “Surface Pretreatment and Adhesion of Thermoplastics Fibre Composites,” J. Mater. Sci., 1988, 7, pp. 625–7.Google Scholar
  7. 7.
    L.Y. Yuan, S.S. Shyu, and J.Y. Lai: “Plasma Surface Treatment of Carbon Fibers. Part 2: Interfacial Adhesion with Poly(Phenylene Sulfide),” Compos. Sci. Technol., 1992, 45, pp. 9–16.CrossRefGoogle Scholar
  8. 8.
    G. Kill, D.H. Hunter, and N.S. McIntyre: “Reactions of Polyethylene Surface with the Downstream Products of an Air Plasma: Gas Phase and Surface Spectroscopic Studies,” J. Polym. Sci.: Part A Polym. Chem., 1996, 34, pp. 2299–2310.CrossRefGoogle Scholar
  9. 9.
    N.K. Anifantis, P.A. Kakavas, and G.C. Papanicolaou: “Thermal Concentration Due to Imperfect Adhesion in Fiber-Reinforced Composites,” Compos. Sci. Technol., 1997, 57, pp. 687–96.CrossRefGoogle Scholar
  10. 10.
    W.G. Pitt, J.E. Lakenan, and A.B. Strong: “The Influence of Plasma Gas Species on the Adhesion of Thermoplastic to Organic Fibers,” J. Appl. Polym. Sci., 1993, 48, pp. 845–56.CrossRefGoogle Scholar
  11. 11.
    B.R.K. Blackman, A.J. Kinloch, and J.F. Watts: “The Plasma Treatment of Thermoplastics Fibre Composites for Adhesive Bonding,” Composites, 1994, 25(5), pp. 332–41.CrossRefGoogle Scholar
  12. 12.
    B.Z. Jang: “Control of Interfacial Adhesion in Continuous Carbon and Kevlar Fiber Reinforced Polymer Composites,” Compos. Sci. Technol., 1992, 44, pp. 333–49.CrossRefGoogle Scholar
  13. 13.
    S. Gao and Y. Zeng: “Surface Modification of Ultrahigh Molecular Weight Polyethylene Fibers by Plasma Treatment,” J. Appl. Polym. Sci., 1993, 47, pp. 2065–71.CrossRefGoogle Scholar
  14. 14.
    D. Ferrante, S. Iannace, and T. Monetta: “Mechanical Strength of Cold Plasma PET Fibers,” J. Mater. Sci., 1998, 33, pp. 1–5.Google Scholar
  15. 15.
    E. Occhiello, M. Morra, G.L. Guerrini, and F. Garbassi: “Adhesion Properties of Plasma-Treated Carbon/PEEK Composites,” Composites, 1992, 23(3), pp. 193–200.CrossRefGoogle Scholar
  16. 16.
    N. Inagaki, S. Tasaka, and Y. Goto: “Surface Modification of Poly-(Tetrafluoroethylene) Film by Plasma Graft Polymerization of Sodium Vinylsulfonate,” J. Appl. Polym. Sci. 1997, 66, pp. 77–84.CrossRefGoogle Scholar
  17. 17.
    I.J. Beyerlein and S.L. Phoenix: “Statistics of Fracture for an Elastic Notched Composites Lamina Containing Weibull Fibres—Part I. Features from Monte-Carlo Simulation,” Eng. Frac. Mech., 1997, 57(2/3), pp. 241–65.CrossRefGoogle Scholar
  18. 18.
    T. Tanaka, H. Nakayama, A. Sakaida, and T. Imamichi: “Evaluation of Weibull Parameters for Static Strengths of Ceramics by Monte Carlo Simulation,” Mater. Sci. Res. Int., 1995, 1(1), pp. 51–58.Google Scholar
  19. 19.
    C. Lipson and N.J. Sheth: “Statistical Distribution” in Statistical Design and Analysis of Engineering Experiments, McGraw-Hill, 1973, pp. 22–66.Google Scholar
  20. 20.
    L. Avérous, J.C. Quantin, and A. Crespy: “Determination of the Microtexture of Reinforced Thermoplastics by Image Analysis,” Compos. Sci. Technol., 1998, 58, pp. 377–87.CrossRefGoogle Scholar
  21. 21.
    B. Chapman: Glow Discharge Processes—Sputtering and Plasma Etching, John Wiley & Sons, New York, 1980, pp. 177–343.Google Scholar
  22. 22.
    Ion and Plasma Beams in Optical Technologies. Scholar

Copyright information

© ASM International 2002

Authors and Affiliations

  • M. O. H. Cioffi
    • 1
  • H. J. C. Voorwald
    • 1
  • V. Ambrogi
    • 2
  • T. Monetta
    • 2
  • F. Bellucci
    • 2
  • L. Nicolais
    • 2
  1. 1.Department of Materials and TechnologyState University of São PauloGuaratinguetá-SPBrazil
  2. 2.Department of Materials and Production EngineeringUniversity of Napoli ‘Federico II’, Piazzale TecchioNapoliItaly

Personalised recommendations