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A new look at tensile yielding in isotactic polypropylene: role of strain rate and thermal softening

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Abstract

Polypropylene (PP) is a semi-crystalline polymer with a very wide range of industrial applications. This is why its mechanical properties, including yielding, have been the subject of numerous studies. The current study has examined the influence of strain rate and thermal softening on yield stress and post yielding behavior of an isotactic PP. A two-process Ree and Eyring model and the heat equation in adiabatic deformation were coupled with a physical parameter described as the temperature sensitivity of the flow stress at yielding, to simulate the effect of gradual temperature rise in adiabatic heating on yielding behavior. Along with that, tensile bars were subjected to tests at different strain rates experimentally. Results showed considerable influence of strain rate on yielding behavior of PP. Two transition points in the yield stress versus strain rate diagram were noticed. The first one occurring at the strain rate of about 7*10–5 s−1 is associated with a shift in deformation mechanism from Process I, i.e., side chain motions, to main chain motions, named Process II. Strain hardening rate increases significantly by moving from Process I to Process II region. The other transition point, equal to 3*10–2 s−1, is the strain rate value at which adiabatic heating surpasses strain hardening. As a result, the positive influence of strain rate on yield stress due to strain hardening stops at this point and temperature starts to rise by further increase in the strain rate. This change from isothermal to adiabatic deformation, causing approximately 2 °C increase in temperature, is associated with the decline of the yield stress and also variations in the post yielding behavior of PP. Stress softening slope and drop after yielding go through a maximum by passing the transition point of 3*10–2 s−1. The effect of strain rate and thermal softening were successfully simulated in terms of decrease in the yield stress and gradual temperature rise above the transition strain rate using the proposed model.

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References

  1. Concise Encyclopedia of Polymer science and Engineering, 2nd Edn, John Wiley & Sons, USA; 1990.

  2. Moore EP Jr (1996) Polypropylene handbook. Hanser Publication, Vienna

    Google Scholar 

  3. Karger-Kocsis J (1999) Polypropylene: an A-Z reference. Kluwer Academic Publishers, Dordrecht

    Book  Google Scholar 

  4. Dasari A, Rohrmann J, Misra RDK (2003) Microstructural evolution during tensile deformation of polypropylenes. Mater Sci Eng, A 351:200–213

    Article  Google Scholar 

  5. Dasari A, Rohrmann J, Misra RDK (2003) Microstructural aspects of surface deformation processes and fracture of tensile strained high isotactic polypropylene. Mater Sci Eng, A 358:372–383

    Article  Google Scholar 

  6. Liu Y, Truss RW (1994) A study of tensile yielding of isotactic polypropylene. J Polym Sci, Part B: Polym Phys 32:2037–2047

    Article  CAS  Google Scholar 

  7. Galeski A (2003) Strength and toughness of crystalline polymer systems. Prog Polym Sci 28:1643–1699

    Article  CAS  Google Scholar 

  8. Liu Y, Kennard CHL, Truss RW, Calos NJ (1997) Characterization of stress-whitening of tensile yield isotactic polypropylene. Polymer 38(11):2797–2805

    Article  CAS  Google Scholar 

  9. Tanniru M, Misra RDK (2006) Reduced susceptibility to stress whitening during tensile deformation of calcium carbonate-reinforced high density polyethylene composites. Mater Sci Eng, A 424:191–204

    Article  Google Scholar 

  10. Schwab R, Ruff V (2013) On the nature of the yield point. Acta Mater 61:1798–1808

    Article  CAS  Google Scholar 

  11. Deblieck RAC, van Beek DJM, Remerie K, Ward IM (2011) Failure mechanisms in polyolefins: the role of crazing, shear yielding and the entanglement network. Polymer 52:2979–2990

    Article  CAS  Google Scholar 

  12. Siviour CR, Jordan JL (2016) High strain rate mechanics of polymers: a review. J Dynamic Behav Mater 2(1):15–32

    Article  Google Scholar 

  13. Dasari A, Misra RDK (2003) On the strain rate sensitivity of high density polyethylene and polypropylenes. Mater Sci Eng, A 358:356–371

    Article  Google Scholar 

  14. Dasari A, Sarang S, Misra RDK (2004) Strain rate sensitivity of homopolymer polypropylene and micrometric wollastonite-filled polypropylene composites. Mater Sci Eng, A 368:191–204

    Article  Google Scholar 

  15. Dasari A, Misra RDK (2004) The Role of Micrometric wollastonite particles on stress whitening behavior of polypropylene composites. Acta Mater 52:1683–1697

    Article  CAS  Google Scholar 

  16. Vu-khank T, Majdoubi MEL (2009) Entropy change with yielding and fracture of polypropylene. Theoret Appl Fract Mech 51:111–116

    Article  Google Scholar 

  17. Ahmed DU, Zhang W, Xu Y, Wang J (2014) Thermal and strain rate sensitive compressive behavior of polycarbonate polymer—experimental and constitutive analysis. J Polym Res 21:519–529

    Article  Google Scholar 

  18. Shui-sheng Y, Yu-bin L, Yong C (2013) The strain-rate effect of engineering materials and its unified model. Latin Am J Solids Struct 10:833–844

    Article  Google Scholar 

  19. Alcock B, Cabrera NO, Barkoula NM, Reynolds CT, Govaert LE, Peijs T (2007) The effect of temperature and strain rate on the mechanical properties of highly oriented polypropylene tapes and all-polypropylene composites. Compos Sci Technol 67:2061–2070

    Article  CAS  Google Scholar 

  20. Hall IH 1968 The effect of strain rate on the stress-strain curve of oriented polymers II The influence of heat developed during extension. Journal of Applied Polymer Science 12: 739–750.

  21. Richeton J, Ahzi S, Vecchio KS, Jiang FC, Adharapurapu RR (2006) Influence of temperature and strain rate on the mechanical behavior of three amorphous polymers: characterization and modeling of the compressive yield stress. Int J Solids Struct 43:2318–2335

    Article  CAS  Google Scholar 

  22. Hopmann Ch., Klein J., Schöngart M 2016 Determination of the strain rate dependent thermal softening behavior of thermoplastic materials for crash simulations. In: Proceedings of PPS-31AIP. https://doi.org/10.1063/1.4942312.

  23. Mallick PK, Zhou Y (2003) Yield and fatigue behavior of polypropylene and polyamide-6 nanocomposites. J Mater Sci 38:3183–3190

    Article  CAS  Google Scholar 

  24. Wang Y, Arruda EM (2006) Constitutive modeling of a thermoplastic olefin over a broad range of strain rates. J Eng Mater Technol 128(4):551–558

    Article  CAS  Google Scholar 

  25. Chou SC, Robertson KD, Rainey JH (1973) The effect of strain rate and heat developed during deformation on the stress–strain curve of plastics. Exp Mech 13(10):422–432

    Article  Google Scholar 

  26. Okerek MI, Buckley CP, Siviour CR (2012) Compression of polypropylene across a wide range of strain rates. Mech Time-Dependent Mater 16:361–379

    Article  Google Scholar 

  27. Pawlak A, Rozanski A, Galeski A (2013) Thermovision studies of plastic deformation and cavitation in polypropylene. Mech Mater 67:104–118

    Article  Google Scholar 

  28. Karger-Kocsis J, Friedrich K (1986) Temperature and strain-rate effects on the fracture toughness of poly (ether ether ketone) its short glass-fiber reinforce composite. Polymer 27:1753–1760

    Article  CAS  Google Scholar 

  29. Eyring H (1936) Viscosity, plasticity, and diffusion as examples of absolute reaction rates. J Chem Phys 4:283–291

    Article  CAS  Google Scholar 

  30. Glasstone S, Laidler KJ, Eyring H (1941) The theory of rate processes. Mc-Graw-Hill, New York, pp 480–483

    Google Scholar 

  31. Ree T., Eyring, H., Eirich, F.R 1958 The relaxation theory of transport phenomena. In: Rheology: Theory and Applications. Academic Press, New York 2: 83

  32. Gómez-del RT, Rodríguez J (2010) Compression yielding of polypropylenes above glass transition temperature. Eur Polymer J 46(6):1244–1250

    Article  Google Scholar 

  33. Fotheringham D, Chery BW (1978) The role of recovery forces in the deformation of linear polyethylene. J Mater Sci 13:951–964

    Article  CAS  Google Scholar 

  34. Richeton J, Ahzi S, Daridon L, Remond Y (2005) A formulation of the cooperative model for the yield stress of amorphous polymers for a wide range of strain rates and temperatures. Polymer 46:6035–6043

    Article  CAS  Google Scholar 

  35. Rault J (1998) Yielding in amorphous and semi-crystalline polymers: the compensation law. J Non-Cryst Solids 235–237:737–741

    Article  Google Scholar 

  36. Gueguen O, Richeton J, Ahzi S, Makradi A (2008) A micromechanically based formulation of the cooperative model for the yield behavior of semi-crystalline polymers. Acta Mater 56:1650–1655

    Article  CAS  Google Scholar 

  37. Robertson RE (1963) On the cold-drawing of plastics. J Appl Polym Sci 7:443–450

    Article  CAS  Google Scholar 

  38. Nasraoui M, Forquin P, Siad L, Rusinek A (2012) Influence of strain rate, temperature and adiabatic heating on the mechanical behaviour of poly-methyl-methacrylate: experimental and modelling analyses. Mater Des 37:500–509

    Article  CAS  Google Scholar 

  39. Hosseinabadi HG, Bagheri R, Gigl T, Hugenschmidt C, Raps D, Altstadt V 2018 Interaction between mechanical response, strain field, and local free volume evolution in glassy polymers Seeking the atomistic origin of post-yield softening. Express Polymer Letters 12 (1): 2–12.

  40. Gunel EM, Basaran C (2010) Stress whitening quantification of thermoformed mineral filled acrylics. J Eng Mater Technol 132:31002–31011

    Article  Google Scholar 

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Authors and Affiliations

  1. Department of Materials Science and Nanotechnology, School of Science and Engineering, Sharif University of Technology, International Campus-Kish Island, Kish Island, Iran

    Mohammad F. Farahani

  2. Polymeric Materials Research Group (PMRG), Department of Materials Science and Engineering, Sharif University of Technology, P.O. Box 11155-9466, Tehran, Iran

    Mohammad F. Farahani & Reza Bagheri

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  1. Mohammad F. Farahani
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  2. Reza Bagheri
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Correspondence to Reza Bagheri.

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Farahani, M.F., Bagheri, R. A new look at tensile yielding in isotactic polypropylene: role of strain rate and thermal softening. Polym. Bull. 79, 11157–11176 (2022). https://doi.org/10.1007/s00289-021-03997-z

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  • DOI: https://doi.org/10.1007/s00289-021-03997-z

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