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Effect of injection molding parameters on crystallinity and mechanical properties of isotactic polypropylene

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  • Published:
International Journal of Plastics Technology

Abstract

The effects of injection molding parameters namely mold temperature, melt temperature and injection speed on crystallization and mechanical properties of isotactic polypropylene were studied. The specimens were molded as per the Taguchi design of experiment and analyzed for signal to noise ratio and for analysis of variance test. The crystallinity and crystal sizes were determined by wide angle X-ray diffraction data. The specimens were tested for tensile, impact, flexural, stress relaxation and dynamic mechanical properties. It was observed that mold temperature was the most influential injection molding parameter governing the crystallinity and other mechanical properties. It was observed that increase in crystallinity is favorable from tensile and flexural strength point of view but impact properties deteriorate with increase in crystallinity. At high injection speed β-phase changes to α-phase due to shear induced orientation of polymer chains. It is interesting to notice that stress relaxation occurred in elastic as well as in plastic regions has the similar trends and can be modeled by the same decay model proposed in this paper.

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References

  1. Kmetty A (2012) Development and characterisation of injection moulded, all-polypropylene composites. Express Polym Lett 7(2):134–145

    Article  Google Scholar 

  2. Kuboki T (2013) Mechanical properties and foaming behavior of injection molded cellulose fiber reinforced polypropylene composite foams. J Cell Plast 50(2):129–143

    Article  Google Scholar 

  3. van der Meer DW (2003) Structure-property relationships in isotactic polypropylene. Twente University Press (TUP), Enschede

    Google Scholar 

  4. Chen Y-H, Mao Y-M, Li Z-M, Hsiao BS (2010) Competitive growth of α- and β-crystals in β-nucleated isotactic polypropylene under shear flow. Macromolecules 43(16):6760–6771

    Article  CAS  Google Scholar 

  5. Chen H, Karger-Kocsis J, Wu J, Varga J (2002) Fracture toughness of α- and β-phase polypropylene homopolymers and random- and block-copolymers. Polymer 43(24):6505–6514

    Article  CAS  Google Scholar 

  6. Tjong SC, Shen JS, Li RKY (1995) Impact fracture toughness of beta-form polypropylene. Scr Metall Mater 33(3):503–508

    Article  CAS  Google Scholar 

  7. Van Erp TB, Balzano L, Peters GWM (2012) Oriented gamma phase in isotactic polypropylene homopolymer. ACS Macro Lett 1(5):618–622

    Article  Google Scholar 

  8. Cho K, Li F, Choi J (1999) Crystallization and melting behavior of polypropylene and maleated polypropylene blends. Polymer 40(7):1719–1729

    Article  CAS  Google Scholar 

  9. Favaro MM, Branciforti MC, Bretas RES (2009) A X-ray study of beta-phase and molecular orientation in nucleated and non-nucleated injection molded polypropylene resins. Mater Res 12(4):455–464

    Article  CAS  Google Scholar 

  10. Jacoby P (2007) Beta nucleating masterbatch offers enhanced properties in polypropylene products. Plast Addit Compd 9(3):32–35

    Article  Google Scholar 

  11. Zhu PW, Edward G (2003) Studies of injection-moulded isotactic poly(propylene) by synchrotron WAXD/SAXS: effects of nucleating agent on morphological distribution. Macromol Mater Eng 288(4):301–311

    Article  CAS  Google Scholar 

  12. van der Burgt FPTJ (2002) Crystallization of isotactic polypropylene, the influence of stereo-defects. Eindhoven Technische Universiteit, Eindhoven

    Google Scholar 

  13. Chen Y-H, Zhong G-J, Wang Y, Li Z-M, Li L (2009) Unusual tuning of mechanical properties of isotactic polypropylene using counteraction of shear flow and β-nucleating agent on β-form nucleation. Macromolecules 42(12):4343–4348

    Article  CAS  Google Scholar 

  14. Dunk R, Bouvart D, Wright DGM, Autran M (1988) The effect of crystallinity on the properties of injection moulded polypropylene and polyacetal. Polymer 29(May):793–796

    Google Scholar 

  15. Weakley-Bollin SC (2010) The effect of injection molding conditions on the near surface rubber morphology, surface chemistry and adhesion performance of semi-crystalline and amorphous polymer. University of Michigan, Ann Arbor

    Google Scholar 

  16. Selvakumar V, Manoharan N (2014) Thermal properties of polypropylene/montmorillonite nanocomposites. Indian J Sci Technol 7(November):136–139

    Google Scholar 

  17. Bhuiyan AH, Mina MF, Seema S, Khan MM, Rahman MJ, Gafur MA (2011) Structural, elastic and thermal properties of titanium dioxide filled isotactic polypropylene. J Polym Res 18(5):1073–1079

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The author is thankful and acknowledge the extension of testing and characterization facilities by Prof. Alim Hussain Naqvi, Prof. Ameer Azam and Dr. Wasi A. Khan, Center of Excellence in Nanotechnology, Department of Applied Physics, Aligarh Muslim University, Aligarh, for this experimental study.

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  1. Department of Petroleum Studies, Faculty of Engineering and Technology, A.M.U., Aligarh, 202001, India

    S. J. A. Rizvi

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Rizvi, S.J.A. Effect of injection molding parameters on crystallinity and mechanical properties of isotactic polypropylene. Int J Plast Technol 21, 404–426 (2017). https://doi.org/10.1007/s12588-017-9194-3

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  • DOI: https://doi.org/10.1007/s12588-017-9194-3

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