Skip to main content
SpringerLink
Log in

An investigation into sintering of PA6 nanocomposite powders for rotational molding

  • Published:
Journal of Thermal Analysis and Calorimetry Aims and scope Submit manuscript

Abstract

The objective of this work is to study the sintering behavior of polyamide 6 (PA6) powders and PA6 nanocomposites by means of thermomechanical (TMA) and dimensionless analysis in view of its technological application in rotational molding. TMA analysis was used to monitor the bulk density evolution of PA6 powders and PA6 nanocomposites when heated above the melting temperature. Experimental TMA results indicate that the sintering of PA6 and PA6 nanocomposites occurs in two different steps, namely powder coalescence and void removal. Furthermore, TMA analysis showed that relevant degradation phenomena occur during the sintering of PA6 and PA6 nanocomposites, leading to gas formation in the molten polymer. The suitability of these materials in rotational molding was then assessed by defining a processing window, as the temperature difference between the endset sintering and the onset degradation. The heating rate dependence of the processing window was explained by means of dimensionless analysis, showing that powder coalescence is influenced by the viscosity evolution of the matrix, whereas void removal is influenced by the gas diffusivity inside the molten matrix. Therefore, the diffusion activation energy correlates the endset sintering temperature to the heating rate. On the other hand, the onset degradation temperature depends on the heating rate, due to the characteristic activation energy of the degradation process. Accordingly, the width of the processing window mainly depends on the values of the activation energies for diffusivity and degradation. The width of the processing window for neat PA6 was found to be too narrow to candidate this polymer for rotational molding. The addition of nanofiller causes a narrowing of the processing window, whereas the PA6 matrix modified with a thermal stabilizer showed a sufficiently broad processing window, compatible for use in rotational molding.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  1. Kandis M, Bergman TL. Observation, prediction, and correlation of geometric shape evolution induced by non-isothermal sintering of polymer powder. J Heat Transf-Trans ASME. 1997;119:824–31.

    Article  CAS  Google Scholar 

  2. Liu SJ. International polymer processing XIII. Munich: Hanser Publishers; 1998.

    Google Scholar 

  3. Bellehumeur CT, Bisaria MK, Vlachopoulos J. An experimental study and model assessment of polymer sintering. Polym Eng Sci. 1996;36:2198–207.

    Article  CAS  Google Scholar 

  4. Kontopoulou M, Vlachopoulos J. Bubble dissolution in molten polymers and its role in rotational molding. Polym Eng Sci. 1999;39:1189–98.

    Article  CAS  Google Scholar 

  5. Greco A, Maffezzoli A. Polymer melting and polymer powder sintering by thermal analysis. J Therm Anal Calorim. 2003;72:1167–74.

    Article  CAS  Google Scholar 

  6. Greco A, Maffezzoli A. Powder-shape analysis and sintering behavior of high-density polyethylene powders for rotational molding. J Appl Polym Sci. 2004;92:449–60.

    Article  CAS  Google Scholar 

  7. Bellehumeur CT, Kontopulou M, Vlachopoulos J. The role of viscoelasticity in polymer sintering. Rheol Acta. 1998;37:270–8.

    Article  CAS  Google Scholar 

  8. Kontopoulou M, Vlachopoulos J. Melting and densification of thermoplastic powders. Polym Eng Sci. 2001;41:155–69.

    Article  CAS  Google Scholar 

  9. Gogos G. Bubble removal in rotational molding. Polym Eng Sci. 2004;44:388–94.

    Article  CAS  Google Scholar 

  10. Rezaei M, Ebrahimi NG, Kontopoulou M. Thermal properties, rheology and sintering of ultra high molecular weight polyethylene and its composites with polyethylene terephthalate. Polym Eng Sci. 2005;45:678–86.

    Article  CAS  Google Scholar 

  11. Drummer D, Rietzel D, Kuhnlein F. Development of a characterization approach for the sintering behavior of new thermoplastics for selective laser sintering. Phys Procedia. 2010;5:533–42.

    Article  CAS  Google Scholar 

  12. Kim J, Creasy TS. Selective laser sintering characteristics of nylon 6/clay-reinforced nanocomposite. Polym Test. 2004;23:629–36.

    Article  CAS  Google Scholar 

  13. Chung H, Das S. Functionally graded nylon-11/silica nanocomposites produced by selective laser sintering. Mater Sci Eng. 2008;487:251–7.

    Article  Google Scholar 

  14. Salmoria GV, Leite JL, Paggi RA. The microstructural characterization of PA6/PA12 blend specimens fabricated by selective laser sintering. Polym Test. 2009;28:746–51.

    Article  CAS  Google Scholar 

  15. Dong L, Makradi A, Ahzi S, Remond Y, Sun X. Simulation of the densification of semicrystalline polymer powders during the selective laser sintering process: application to nylon 12. Polym Sci Ser A. 2008;50:704–9.

    Article  Google Scholar 

  16. Asgarpour M, Bakir F, Khelladi S, Khavandi A, Tcharkhtchi A. Characterization and modeling of sintering of polymer particles. J Appl Polym Sci. 2001;119:2784–92.

    Article  Google Scholar 

  17. Jain PK, Pandey PM, Rao PVM. Selective laser sintering of clay-reinforced polyamide. Polym Compos. 2010;31:732–43.

    CAS  Google Scholar 

  18. Oliveira MJ, Cramez MC, Garcia CB, Kearns MP, Maziers E. Effect of the processing conditions on the microstructure and properties of rotational molded polyamide 11. J Appl Polym Sci. 2008;108:939–46.

    Article  CAS  Google Scholar 

  19. Opfermann J, Blumm J, Emmerich WD. Simulation of the sintering behavior of a ceramic green body using advanced thermokinetic analysis. Thermochim Acta. 1998;318:213–20.

    Article  CAS  Google Scholar 

  20. Greco A, Strafella A, La Tegola C, Maffezzoli A. Assessment of the relevance of sintering in thermoplastic commingled yarn consolidation. Polym Compos. 2011;32(4):657–64.

    Article  CAS  Google Scholar 

  21. Dealy JM, Larson RG. Structure and rheology of molten polymers. Munich: Carl Hanser Verlag; 2006.

    Book  Google Scholar 

  22. Ojovan MI, Lee WE. Fragility of oxide melts as a thermodynamic parameter. Phys Chem Glasses. 2005;46(1):7–11.

    CAS  Google Scholar 

  23. Vogel H. The law of temperature dependence of the viscosity of fluids. Phys Z. 1921;22:65.

    Google Scholar 

  24. Greco A, Maffezzoli A, Vlachopoulos J. Simulation of heat transfer during rotational molding. Adv Polym Tech. 2003;22:271–9.

    Article  CAS  Google Scholar 

  25. Shah RK, Paul DR. Organoclay degradation in melt processed polyethylene nanocomposites. Polymer. 2006;47:4075–84.

    Article  CAS  Google Scholar 

  26. Esposito Corcione C, Cavallo A, Pesce E, Greco A, Maffezzoli A. Evaluation of the degree of dispersion of nanofillers by mechanical, rheological, and permeability analysis. Polym Eng Sci. 2011;51:1280–5.

    Article  Google Scholar 

  27. Esposito Corcione C, Mensitieri G, Maffezzoli A. Analysis of the structure and mass transport properties of nanocomposite polyurethane. Polym Eng Sci. 2009;49:1708–18.

    Article  CAS  Google Scholar 

  28. Son Y. Measurement of interfacial tension between polyamide-6 and poly(styrene-co-acrylonitrile) by breaking thread method. Polymer. 2001;42:1287–91.

    Article  CAS  Google Scholar 

  29. Van Krevelen DW, te Nijenhuis K. Properties of polymers. 4th ed. Amsterdam: Elsevier; 2009.

    Google Scholar 

Download references

Acknowledgements

Authors wish to thank the “Regione Puglia” for financial support of the project “INCOR—Innovative thermoplastic matrix composites for rotational moulding”.

Author information

Authors and Affiliations

  1. Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100, Lecce, Italy

    Antonio Greco & Alfonso Maffezzoli

  2. Advanced Physical Technologies and New Materials Department, ENEA—Italian National Agency for New Technologies, Energy and the Environment, S.S. 7—Km 714, 72100, Brindisi, Italy

    Emanuela Calò, Claudia Massaro & Roberto Terzi

Authors
  1. Antonio Greco
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Alfonso Maffezzoli
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Emanuela Calò
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Claudia Massaro
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Roberto Terzi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Antonio Greco.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Greco, A., Maffezzoli, A., Calò, E. et al. An investigation into sintering of PA6 nanocomposite powders for rotational molding. J Therm Anal Calorim 109, 1493–1502 (2012). https://doi.org/10.1007/s10973-011-1916-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10973-011-1916-8

Keywords

Search

Navigation