Advertisement

Simulation of Solidification of a Nucleated Isotactic Polypropylene in a Quiescent Condition

  • Hamed NokhostinEmail author
  • Christian Hopmann
Conference paper
  • 41 Downloads

Abstract

Nucleating agents play an important role as additives in the production of injection-moulded components from semi-crystalline thermoplastics. To date, however, no work has been published in the scientific literature, which simulates the influence of nucleating agents on the formation of the microstructure of semi-crystalline thermoplastics. This research gap is to be closed within the framework of the research.

The aim of previous researches at the Institute for Plastics Processing (IKV) was to predict the microstructure of injection-moulded components using an in-house developed model to describe the crystallisation of semi-crystalline thermoplastics, which was implemented into software, called “SphaeroSim”. Although, it was able to simulate only a homogeneous pure melt without any additive. Within this work, the SphaeroSim is further developed to consider the additives and to distinguish between alpha- and beta nucleating agents. To consider the nucleating agents, the possibility to set up predefined nuclei is added to the model. Finally, the growth rate of beta crystals is measured on the hot stage at different temperatures to realise the consideration of beta nucleating agents. Finally, the solidification process on the hot stage is simulated and compared to the experimental results.

Keywords

Crystallisation Semi-crystalline thermoplastics Multi-scale simulation 

Notes

Acknowledgment

This dedicated research has been funded by the Deutsche Forschungsgemeinschaft (DFG) as a part of the project “Simulation of the development of the microstructure of injection-moulded semi-crystalline thermoplastics by means of a multi-scale approach under consideration of shear-induced crystal forms (alpha and beta)” (Project-ID: HO 4776/53-1). We would like to extend our thanks to the DFG.

References

  1. 1.
    Tordjeman, P., Robert, C., Marin, G., Gerard, P.: The effect of α, β crystalline structure on the mechanical properties of polypropylene. Eur. Phys. J. 4(4), 459–465 (2001)Google Scholar
  2. 2.
    Wypych, G.: Handbook of Nucleating Agents. ChemTec Publishing, Canada (2016)Google Scholar
  3. 3.
    Palza, H., Vera, J., Wilhelm, M., Zapata, P.: Spherulite growth rate in polypropylene/silica nanoparticle composites: effect of particle morphology and compatibilizer. Macromol. Mater. Eng. 296(8), 744–751 (2011)CrossRefGoogle Scholar
  4. 4.
    Xu, T., Zhang, A., Zhao, Y., Han, Z., Xue, L.: Crystallization kinetics and morphology of biodegradable poly(lactic acid) with a hydrazide nucleating agent. Polym. Test. 45, 101–106 (2015)CrossRefGoogle Scholar
  5. 5.
    Petchwattana, N., Covavisaruch, S., Sripanya, P.: Effect of nano-scaled styrene butadiene rubber based nucleating agent on the thermal, crystallization and physical properties of isotactic polypropylene. J. Alloys Compd. 582, 190–195 (2014)CrossRefGoogle Scholar
  6. 6.
    Karger-Kocsis, J.: How does “phase transformation toughening” work in semicrystalline polymers? Polym. Eng. Sci. 36(2), 203–210 (1996)CrossRefGoogle Scholar
  7. 7.
    Varley, R.J., Dell’Olio, M., Yuan, Q., Khor, S., Leong, K.H., Bateman, S.: Different β nucleants and the resultant microstructural, fracture, and tensile properties for filled and unfilled ISO polypropylene. J. Appl. Polym. Sci. 128(1), 619–627 (2013)CrossRefGoogle Scholar
  8. 8.
    Zhang, Y., Zhang, L., Liu, H., Du, H., Zhang, J., Wang, T., Zhang, X.: Novel approach to tune mechanics of β-nucleation agent nucleated polypropylene: role of oriented β spherulite. Polymer 54(21), 6026–6035 (2013)CrossRefGoogle Scholar
  9. 9.
    Kersch, M., Schmidt, H.W., Altstädt, V.: Influence of different beta-nucleating agents on the morphology of isotactic polypropylene and their toughening effectiveness. Polymer 98, 320–326 (2016)CrossRefGoogle Scholar
  10. 10.
    Michler, G.H., Balta-Calleja, F.J.: Nano- and Micromechanics of Polymers. Hanser, München (2012)CrossRefGoogle Scholar
  11. 11.
    Laschet, G., Spekowius, M., Spina, R., Hopmann, C.: Multiscale simulation to predict microstructure dependent effective elastic properties of an injection molded polypropylene component. Mech. Mater. 105, 123–137 (2017)CrossRefGoogle Scholar
  12. 12.
    Spina, R., Spekowius, R., Hopmann, C.: Multiphysics simulation of thermoplastic polymer crystallization. Mater. Des. 105, 455–469 (2016)CrossRefGoogle Scholar
  13. 13.
    Wienke, S., Spekowius, M., Dammer, A., Mey, D.A., Hopmann, C., Müller, M.S.: Towards an accurate simulation of the crystallization process in injection molded plastic components by hybrid parallelization. Int. J. High Perform. Comput. Appl. 28(3), 356–367 (2013)CrossRefGoogle Scholar
  14. 14.
    Spina, R., Spekowius, M., Hopmann, C.: Analysis of polymer crystallization with a multiscale modeling approach. Key Eng. Mater. 611, 928–936 (2014)CrossRefGoogle Scholar
  15. 15.
    Lamberti, G.: A direct way to determine iPP density nucleation from DSC isothermal measurements. Polym. Bull. 52(6), 443–449 (2004)CrossRefGoogle Scholar
  16. 16.
    Spekowius, M.: New Microscale Model for the Description of Crystallization of Semi-Crystalline Thermoplastics. Verlag Mainz, Aachen (2017)Google Scholar
  17. 17.
    Lotz, B.: α and β phases of isotactic polypropylene: a case of growth kinetics `phase reentrency’ in polymer crystallization. Polymer 39(19), 4561–4567 (1998)CrossRefGoogle Scholar
  18. 18.
    Lovinger, A.J., Chua, J.O., Gryte, C.C.: Studies on the α and β forms of isotactic polypropylene by crystallization in a temperature gradient. J. Polym. Sci. Polym. Phys. Ed. 15(4), 641–656 (1977)CrossRefGoogle Scholar
  19. 19.
    Zhang, B., Chen, J., Zhang, X., Shen, C.: Formation of β-cylindrites under supercooled extrusion of isotactic polypropylene at low shear stress. Polymer 52(9), 2075–2084 (2011)CrossRefGoogle Scholar
  20. 20.
    Nakamura, K., Shimizu, S., Umemoto, S., Thierry, A., Lotz, B., Okui, N.: Temperature dependence of crystal growth rate for α and β forms of isotactic polypropylene. Polym. J. 40, 915 (2008)CrossRefGoogle Scholar
  21. 21.
    Janeschitz-Kriegl, H.: Crystallization Modalities in Polymer Melt Processing. Springer, Wien (2010)CrossRefGoogle Scholar
  22. 22.
    Ziabicki, A.: Generalized theory of nucleation kinetics. IV. Nucleation as diffusion in the space of cluster dimensions, positions, orientations, and internal structure. J. Chem. Phys. 85(5), 3042–3057 (1986)CrossRefGoogle Scholar
  23. 23.
    Hoffman, J.D., Davis, G.T., Lauritzen, J.I.: The rate of crystallization of linear polymers with chain folding. In: Hannay, N.B. (ed.) Treatise on Solid State Chemistry. Springer, New York (1976)Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2020

Authors and Affiliations

  1. 1.Institute for Plastics Processing (IKV)AachenGermany

Personalised recommendations