Journal of Thermal Analysis and Calorimetry

, Volume 109, Issue 2, pp 863–873 | Cite as

Thermal stability of high density polyethylene–fumed silica nanocomposites



High-density polyethylene-based nanocomposites were prepared through a melt compounding process by using surface functionalized fumed silica nanoparticles in various amounts, in order to investigate their capability to improve both mechanical properties and resistance to thermal degradation. The fine dispersion of silica aggregates led to noticeable improvements of both the elastic modulus and of the stress at yield proportionally to the filler content, while the tensile properties at break were not impaired even at elevated filler content. Thermogravimetric analysis showed that the selected nanoparticles were extremely effective both in increasing the decomposition temperature and in decreasing the mass loss rate, even at relatively low filler loadings. The formation of a char enriched layer, limiting the diffusion of the oxygen through the nanofilled samples, was responsible of noticeable improvements of the limiting oxygen index, especially at elevated silica loadings. In contrast with commonly reported literature results, cone calorimeter tests also revealed the efficacy of functionalized nanoparticles in delaying the time to ignition and in decreasing the heat release rate values. Therefore, the addition of functionalized fumed silica nanoparticles could represent an effective way to enhance the flammability properties of polyolefin matrices even at low filler concentrations.


Polyethylene Silica Nanocomposites Thermal properties 



Dr. Denis Lorenzi and Ing. Fabio Cuttica are gratefully acknowledged for their support to the experimental work.


  1. 1.
    Bondioli F, Dorigato A, Fabbri P, Messori M, Pegoretti A. High-density polyethylene reinforced with submicron titania particles. Polym Eng Sci. 2008;48:448–57.CrossRefGoogle Scholar
  2. 2.
    Bondioli F, Dorigato A, Fabbri P, Messori M, Pegoretti A. Improving the creep stability of high-density polyethylene with acicular titania nanoparticles. J Appl Polym Sci. 2009;112:1045–55.CrossRefGoogle Scholar
  3. 3.
    Mandalia T, Bargaya F. Organo-clay mineral-melted polyolefin nanocomposites. Effect of surfactant/CEC ratio. J Phys Chem Solids. 2005;67:836–45.CrossRefGoogle Scholar
  4. 4.
    Yuan Q, Misra RDK. Impact fracture behaviour of clay-reinforced polypropylene nanocomposites. Polymer. 2006;47:4421–33.CrossRefGoogle Scholar
  5. 5.
    Zhang Z, Yang JL, Friedrich K. Creep resistant polymeric nanocomposites. Polymer. 2004;45:3481–5.CrossRefGoogle Scholar
  6. 6.
    Zhao C, Qin H, Gong F, Feng M, Zhang S, Yang M. Mechanical, thermal and flammability properties of polyethylen/clay nanocomposites. Polym Degrad Stab. 2005;87:183–9.CrossRefGoogle Scholar
  7. 7.
    Zhang MQ, Rong MZ, Zhang HB, Friedrich K. Mechanical properties of low nano-silica filled high density polyethylene composites. Polym Eng Sci. 2003;43(2):490–500.CrossRefGoogle Scholar
  8. 8.
    Zhang J, Jiang DD, Wilkie CA. Polyethylene and polypropylene nanocomposites based upon an oligomerically modified clay. Thermochim Acta. 2005;430:107–13.CrossRefGoogle Scholar
  9. 9.
    Pegoretti A, Dorigato A, Penati A. Tensile mechanical response of polyethylene–clay nanocomposites. Express Pol Lett. 2007;1(3):123–31.CrossRefGoogle Scholar
  10. 10.
    Starkova O, Yang JL, Zhang Z. Application of time-stress superposition to nonlinear creep of polyamide 66 filled with nanoparticles of various sizes. Compos Sci Technol. 2007;67:2691.CrossRefGoogle Scholar
  11. 11.
    Choi WJ, Kim SH, Kim YJ, Kim SC. Synthesis of chain-extended organifier and properties of polyurethane–clay nanocomposites. Polymer. 2004;45(17):6045–57.CrossRefGoogle Scholar
  12. 12.
    Gorrasi M, Tortora M, Vittoria G. Synthesis and physical properties of layered silicates/polyurethane nanocomposites. J Polym Sci B. 2005;43(18):2454–67.CrossRefGoogle Scholar
  13. 13.
    Tortora M, Gorrasi M, Vittoria G, Galli V, Ritrovati S, Chiellini E. Structural characterization and transport properties of organically modified montmorillonite/polyurethane nanocomposites. Polymer. 2002;43(23):6147–57.CrossRefGoogle Scholar
  14. 14.
    Zhang M, Sundararaj U. Thermal, rheological, and mechanical behaviors of LLDPE/PEMA/clay nanocomposites: effect of interaction between polymer, compatibilizer, and nanofiller. Macromol Mater Eng. 2006;291:697–706.CrossRefGoogle Scholar
  15. 15.
    Ou CF, Hsu MC. Preparation and properties of cycloolefin copolymer/silica hybrids. J Appl Polym Sci. 2007;104:2542–8.CrossRefGoogle Scholar
  16. 16.
    Ou CF, Hsu MC. Preparation and characterization of cyclo olefin copolymer (COC)/silica nanoparticle composites by solution blending. J Polym Res. 2007;14:373–8.CrossRefGoogle Scholar
  17. 17.
    Kolarik J, Fambri L, Pegoretti A, Penati A, Goberti P. Prediction of the creep of heterogeneous polymer blends: rubber-toughened polypropylene/poly(styrene-co-acrylonitrile). Polym Eng Sci. 2002;42(1):161–9.CrossRefGoogle Scholar
  18. 18.
    Kolarik J, Pegoretti A, Fambri L, Penati A. Non linear long term tensile creep of polypropylene/cycloolefin copolymer blends with fibrous structure. Macromol Mater Eng. 2003;288:629–41.CrossRefGoogle Scholar
  19. 19.
    Pegoretti A. Creep and fatigue behaviour of polymer nanocomposites. In: Karger-Kocsis J, Fakirov S, editors. Nano- and micromechanics of polymer blends and composites. Munich: Carl Hanser Verlag GmbH & Co. KG; 2009. p. 301–39.Google Scholar
  20. 20.
    Bergaya F, Mandalia T, Amigouet P. A brief survey on CLAYPEN and Nanocomposites based on unmodified PE and organo-pillared clays. Colloid Polym Sci. 2005;283:773–82.CrossRefGoogle Scholar
  21. 21.
    Su S, Jiang DD, Wilkie CA. Poly(methyl methacrylate), polypropylene and polyethylene nanocomposite formation by melt blending using novel polymerically modified clay. Polym Degrad Stab. 2004;83:321–31.CrossRefGoogle Scholar
  22. 22.
    Wang KH, Xu M, Choi YS, Chung IJ. Effect of aspect ratio on melt extensional process of maleated polyethylene/clay nanocomposites. Polym Bull. 2001;46:499–595.CrossRefGoogle Scholar
  23. 23.
    Lu H, Hu Y, Xiao J, Kong Q, Chen Z, Fan W. The influence of irradiation on morphology evolution and flammability properties of maleated polyethylene/clay nanocomposite. Mater Lett. 2005;59:648–51.CrossRefGoogle Scholar
  24. 24.
    Ranade A, Nayak K, Fairbrother D, D’ Souza NA. Maleated and non maleated polyethylene-montmorillonite layered silicate blown films: creep, dispersion and crystallinity. Polymer. 2005;46:7323–33.CrossRefGoogle Scholar
  25. 25.
    Costantino U, Gallipoli A, Nocchetti M, Camino G, Bellucci F, Frache A. New nano-composites constituted of polyethylene and organically modified ZnAl-hydrotalcites. Polym Degrad Stab. 2005;90:586–90.CrossRefGoogle Scholar
  26. 26.
    Costantino U, Montanari F, Nocchetti M, Canepa F, Frache A. Preparation and characterization of hydrotalcite/carboxy-adamantane intercalation compounds as fillers of polymeric nanocomposites. J Mater Chem. 2007;17:1079–86.CrossRefGoogle Scholar
  27. 27.
    Gilman JW. Flammability and thermal stability studies of polymer layered-silicate (clay) nanocomposites. Appl Clay Sci. 1999;15(1–2):31–49.CrossRefGoogle Scholar
  28. 28.
    Kiliaris P, Papaspyrides CD. Polymer/layered silicate (clay) nanocomposites: an overview of flame retardancy. Prog Polym Sci. 2010;35:902–58.CrossRefGoogle Scholar
  29. 29.
    Dorigato A, Pegoretti A, Penati A. Linear low-density polyethylene/silica micro- and nanocomposites: dynamic rheological measurements and modelling. Express Pol Lett. 2010;4(2):115–29.CrossRefGoogle Scholar
  30. 30.
    Dorigato A, Dzenis Y, Pegoretti A. Nanofiller aggregation as reinforcing mechanism in nanocomposites. Procedia Eng. 2011;10:894-899.Google Scholar
  31. 31.
    Dorigato A, Fambri L, Pegoretti A, Slouf M, Kolarik J. Cycloolefin copolymer (COC)/fumed silica nanocomposites. J Appl Polym Sci. 2011;119:3393–402.CrossRefGoogle Scholar
  32. 32.
    Dorigato A, Pegoretti A. Tensile creep behaviour of polymethylpentene/silica nanocomposites. Polym Int. 2010;59:719–24.Google Scholar
  33. 33.
    Dorigato A, Pegoretti A, Kolarik J. Nonlinear tensile creep of linear low density polyethylene/fumed silica nanocomposites: time-strain superposition and creep prediction. Polym Compos. 2010;31:1947–55.CrossRefGoogle Scholar
  34. 34.
    Kontou E, Niaounakis M. Thermo-mechanical properties of LLDPE/SiO2 nanocomposites. Polymer. 2006;47:1267–80.CrossRefGoogle Scholar
  35. 35.
    Barus S, Zanetti M, Lazzari M, Costa L. Preparation of polymeric hybrid nanocomposites based on PE and nanosilica. Polymer. 2009;50:2595–600.CrossRefGoogle Scholar
  36. 36.
    Chrissafis K, Paraskevopoulos KM, Pavlidou E, Bikiaris D. Thermal degradation mechanism of HDPE nanocomposites containing fumed silica nanoparticles. Thermochim Acta. 2009;485:65–71.CrossRefGoogle Scholar
  37. 37.
    Chrissafis K, Paraskevopoulos KM, Tsiaoussis I, Bikiaris D. Comparative study of the effect of different nanoparticles on the mechanical properties, permeability, and thermal degradation mechanism of HDPE. J Appl Polym Sci. 2009;114:1606–18.CrossRefGoogle Scholar
  38. 38.
    Dorigato A, D’Amato M, Pegoretti A. Thermo-mechanical properties of high density polyethylene - fumed silica nanocomposites: effect of filler surface area and treatment. J Polym Res. 2012 (in press).Google Scholar
  39. 39.
    Sinha Ray S, Okamoto M. Polymer/layered silicate nanocomposites: a review from preparation to processing. Prog Polym Sci. 2003;28:1539–641.CrossRefGoogle Scholar
  40. 40.
    Vassiliou A, Bikiaris D, Pavlidou E. Optimizing melt-processing conditions for the preparation of iPP/fumed silica nanocomposites: morphology, mechanical and gas permeability properties. Macromol React Eng. 2007;1:488–501.CrossRefGoogle Scholar
  41. 41.
    Naveau E, Dominkovics Z, Detrembleur C, Jérôme C, Hári J, Renner K, et al. Effect of clay modification on the structure and mechanical properties of polyamide-6 nanocomposites. Eur Polym J. 2011;47(1):5–15.CrossRefGoogle Scholar
  42. 42.
    Pukanszky B, Demjen Z. Silane treatment in polypropylene composites: adsorption and coupling. Macromol Symp. 1999;139:93–105.CrossRefGoogle Scholar
  43. 43.
    Ábrányi Á, Százdi L, Pukánszky B, Vancsó GJ. Formation and detection of clay network structure in poly(propylene)/layered silicate nanocomposites. Macromol Rapid Commun. 2006;27(2):132–5.CrossRefGoogle Scholar
  44. 44.
    Lertwimolnun W, Vergnes B. Influence of compatibilizer and processing conditions on the dispersion of nanoclay in a polypropylene matrix. Polymer. 2005;46(10):3462–71.CrossRefGoogle Scholar
  45. 45.
    Akbari B, Bagheri R. Deformation mechanism of epoxy/clay nanocomposite. Eur Polym J. 2007;43:782–8.CrossRefGoogle Scholar
  46. 46.
    Shen L, Du Q, Wang H, Zhong W, Yang Y. In situ polymerization and characterization of polyamide-6/silica nanocomposites derived from water glass. Polym Int. 2004;53:1153–60.CrossRefGoogle Scholar
  47. 47.
    Gungor A. The physical and mechanical properties of polymer composites filled with Fe powder. J Appl Polym Sci. 2006;99:2438–42.CrossRefGoogle Scholar
  48. 48.
    Pan M, Shi X, Li X, Hu H, Zhang L. Morphology and properties of PVC/Clay nanocomposites via in situ emulsion polymerization. J Appl Polym Sci. 2004;94:277–86.CrossRefGoogle Scholar
  49. 49.
    Bikiaris DN, Vassiliou A, Pavlidou E, Karayannidis GP. Compatibilisation effect of PP-g-MA copolymer on iPP/SiO2 nanocomposites prepared by melt mixing. Eur Polym J. 2005;41:1965–78.CrossRefGoogle Scholar
  50. 50.
    Costa FR, Wagenknecht U, Heinrich G. LDPE/Mg–Al layered double hydroxide nanocomposite: thermal and flammability properties. Polym Degrad Stab. 2007;92:1813–23.CrossRefGoogle Scholar
  51. 51.
    Garcia N, Hoyos M, Guzman J, Tiemblo P. Comparing the effect of nanofillers as thermal stabilizers in low density polyethylene. Polym Degrad Stab. 2009;94:39–48.CrossRefGoogle Scholar
  52. 52.
    Leszczynska A, Njuguma J, Pielichowski K, Banerjee JR. Polymer/montmorillonite nanocomposites with improved thermal properties. Part I. Factors influencing thermal stability and mechanisms of thermal stability improvement. Thermochim Acta. 2007;453:75–96.CrossRefGoogle Scholar
  53. 53.
    Stark NM, White RH, Mueller SA, Osswald TA. Evaluation of various fire retardants for use in wood flourepolyethylene composites. Polym Degrad Stab. 2010;95:1903–10.CrossRefGoogle Scholar
  54. 54.
    Minkova L, Peneva Y, Tashev E, Filippi S, Pracella M, Magagnini P. Thermal properties and microhardness of HDPE/clay nanocomposites compatibilized by different functionalized polyethylenes. Polym Test. 2009;28:528–33.CrossRefGoogle Scholar
  55. 55.
    Elias HG. An introduction to plastics. Weinheim: Wiley-VCH; 2003.Google Scholar
  56. 56.
    Cassagnau P. Melt rheology of organoclay and fumed silica nanocomposites. Polymer. 2008;49:2183–96.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2012

Authors and Affiliations

  1. 1.Department of Materials Engineering and Industrial Technologies (DIMTI)University of TrentoTrentoItaly
  2. 2.Department of Materials Science and Chemical Engineering (DISMIC)Polytechnic of TurinAlessandriaItaly

Personalised recommendations