Journal of Thermal Analysis and Calorimetry

, Volume 138, Issue 4, pp 2469–2480 | Cite as

Recycled polypropylene with improved thermal stability and melt processability

  • Sergiu Alexandru Stoian
  • Augusta Raluca Gabor
  • Ana-Maria Albu
  • Cristian Andi Nicolae
  • Valentin Raditoiu
  • Denis Mihaela PanaitescuEmail author


Polypropylene (PP) is a versatile polymer, with a wide range of applications, from household appliances to packaging and automotive components. Unfortunately, most of the PP products have a short life, which leads to a large amount of plastic waste. Recycling PP is an efficient way to offset the environmental pressure, and several technical solutions have been already proposed for PP recycling. However, dramatically reduced thermal and mechanical properties are generally obtained in the case of PP waste materials. In this work, the influence of PP waste on thermal and mechanical properties of PP waste/virgin PP blends was studied. A PP waste material (PPRR) was melted and compounded with high flow virgin PP homopolymer. The blends were characterized by dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, mechanical tests and Fourier transform infrared spectroscopy. An increase by 20% of the tensile strength and modulus and 2.5 times increase in the melt flow index were observed in the case of the blend with 50% virgin PP as compare to PPRR, also an important increase in crystallinity. All the blends showed a better thermal stability than the virgin PP. The results recommend the blends with 30–50% virgin PP for the recycling of PP waste from raffia in high-performance applications.


Compounding Polymer blends Polypropylene Recycled polypropylene Thermal analysis 



This work was supported by a grant of the Romanian Ministry of Research and Innovation, CHEM-ERGENT, Contract No. 23N/2018 (PN within Program NUCLEU.


  1. 1.
    Makoto K, Arimitsu U, Naoki H, Hirotaka O, Masaya K. Development and applications of polyolefin- and rubber–clay nanocomposites. Polym J. 2011;43:583–93.CrossRefGoogle Scholar
  2. 2.
    Khalaj MJ, Ahmadi H, Lesankhosh R, Khalaj G. Study of physical and mechanical properties of polypropylene nanocomposites for food packaging application: nano-clay modified with iron nanoparticles. Trends Food Sci Technol. 2016;51:41–8.CrossRefGoogle Scholar
  3. 3.
    Huan TD, Boggs S, Teyssedre G, Laurent C, Cakmak M, Kumar S, Ramprasad R. Advanced polymeric dielectrics for high energy density applications. Prog Mater Sci. 2016;83:236–69.CrossRefGoogle Scholar
  4. 4.
    Panaitescu DM, Vuluga Z, Ghiurea M, Iorga M, Nicolae CA, Gabor RA. Influence of compatibilizing system on morphology, thermal and mechanical properties of high flow polypropylene reinforced with short hemp fibers. Compos Part B Eng. 2015;69:286–95.CrossRefGoogle Scholar
  5. 5.
    Panaitescu DM, Vuluga Z, Radovici C, Nicolae CA. Morphological investigation of PP/nanosilica composites containing SEBS. Polym Test. 2012;31:355–65.CrossRefGoogle Scholar
  6. 6.
    Scheirs J. Polymer recycling. New York: Wiley; 1998.Google Scholar
  7. 7.
    Hamad K, Kaseem M, Deri F. Recycling of waste from polymer materials: an overview of the recent works. Polym Degrad Stab. 2013;98:2801–12.CrossRefGoogle Scholar
  8. 8.
    Ghioca P, Spurcaciu B, Iancu L, Grigorescu R, Rapa M, Grosu E, Matei E, Berbecaru C, Pica A, Gardu R, Cincu C. Composite of waste polypropylene by styrene-isoprene block-copolymers blending. Mater Plast. 2015;52:3.Google Scholar
  9. 9.
    Ferrándiz S, López J, Navarro R, Parres F. Rheological behavior of recycled polypropylene for reuse in the automotive sector. J Optoelectron Adv Mater. 2011;13:902–5.Google Scholar
  10. 10.
    Bodzay B, Fejos M, Bocz K, Toldy A, Ronkay F, Marosi G. Upgrading of recycled polypropylene by preparing flame retarded layered composite. eXPRESS Polym Lett. 2012;6:895–902.CrossRefGoogle Scholar
  11. 11.
    Jmal H, Bahlouli N, Wagner-Kocher C, Leray D, Ruch F, Munsch JN, Nardin M. Influence of the grade on the variability of the mechanical properties of polypropylene waste. Waste Manag. 2018;75:160–73.CrossRefGoogle Scholar
  12. 12.
    Ragaert K, Hubo S, Delva L, Veelaert L, Bois E. Upcycling of contaminated post-industrial polypropylene waste: a design from recycling case study. Polym Eng Sci. 2018;58:528–34.CrossRefGoogle Scholar
  13. 13.
    Väntsi O, Kärki T. Environmental assessment of recycled mineral wool and polypropylene utilized in wood polymer composites. Resour Conserv Recycl. 2015;104:38–48.CrossRefGoogle Scholar
  14. 14.
    Aurrekoetxea J, Sarrionandia MA, Urrutibeascoa I, Maspoch ML. Effects of recycling on the microstructure and the mechanical properties of isotactic polypropylene. J Mater Sci. 2001;36:2607–13.CrossRefGoogle Scholar
  15. 15.
    Zdiri K, Elamri A, Hamdaoui M, Harzallah O, Khenoussi N, Brendlé J. Reinforcement of recycled PP polymers by nanoparticles incorporation. Green Chem Lett Rev. 2018;11(3):296–311.CrossRefGoogle Scholar
  16. 16.
    Mehmet SE, Emel O. Mechanical and thermal behaviors of polypropylene—multi-walled carbon nanotube nanocomposite monofilaments. Fibres Text East Eur. 2013;1:21.Google Scholar
  17. 17.
    Bahlouli N, Pessey D, Raveyre C, Guillet J, Ahzi S, Dahoun A, Hiver JM. Recycling effects on the rheological and thermomechanical properties of polypropylene-based composites. Mater Des. 2012;33:451–8.CrossRefGoogle Scholar
  18. 18.
    Mothé CG, Monteiro DF, Mothé MG. Dynamic mechanical and thermal behavior analysis of composites based on polypropylene recycled with vegetal leaves. Mater Sci Appl. 2016;7:349–57.Google Scholar
  19. 19.
    Karger-Kocsis J. Structure and morphology, in polypropylene: structure, blends and composites, vol. 1. London: Chapman & Hall; 1995.CrossRefGoogle Scholar
  20. 20.
    Ramos VD, Costa HM. Degradation of polypropylene (PP) during multiple extrusions: thermal analysis. Polym Test. 2007;26:676–84.CrossRefGoogle Scholar
  21. 21.
    Zhou TY, Tsui GCP, Liang JZ, Zou SY, Tang CY. Thermal properties and thermal stability of PP/MWCNT composites. Compos Part B. 2016;90:107–14.CrossRefGoogle Scholar
  22. 22.
    Ozen I, Simsek S, Eren F. Production and characterization of polyethylene/calcium carbonate composite materials by using calcium carbonate dry and wet coated with different fatty acids. Polym Polym Compos. 2013;21:3.Google Scholar
  23. 23.
    Deshmukh GS, Pathak SU, Peshwe DR, Ekhe JD. Effect of uncoated calcium carbonate and stearic acid coated calcium carbonate on mechanical, thermal and structural properties of poly(butylene terephthalate) (PBT)/calcium carbonate composites. Bull Mater Sci. 2010;33(3):277–84.CrossRefGoogle Scholar
  24. 24.
    Loof D, Hiller M, Oschkinat H, Koschek K. Quantitative and qualitative analysis of surface modified cellulose utilizing TGA-MS. Mater. 2016;9:415.CrossRefGoogle Scholar
  25. 25.
    Borysiak S. The thermo-oxidative stability and flammability of wood/polypropylene composites. J Therm Anal Calorim. 2015;119:1955–62.CrossRefGoogle Scholar
  26. 26.
    Hafshejani KT, Khorasani SN, Jahadi M, Hafshejani MS, Neisiany RE. Improving mechanical and thermal properties of high-density polyethylene/wood flour nanocomposites. J Therm Anal Calorim. 2019;137:175–83.CrossRefGoogle Scholar
  27. 27.
    Cibulkova Z, Vykydalova A, Chochulova A, Simon P, Alexy P, Omanikova L. Thermooxidative stability of polypropylene/TiO2 and polypropylene/layered silicate nanocomposites. J Therm Anal Calorim. 2018;131:1491–7.CrossRefGoogle Scholar
  28. 28.
    Socrates G. Infrared and Raman characteristic group frequencies: tables and charts. 3rd ed. Middlesex: The University of West London; 2001.Google Scholar
  29. 29.
    Gonzalez JAC, López RE, Saldivar RG, Almendarez AC. Improvement in the energy dissipation capacity of polypropylene composites through a surface modification of titanium dioxide particles with a dicarboxylic acid. Thermochim Acta. 2018;664:48–56.CrossRefGoogle Scholar
  30. 30.
    Matei E, Râpa M, Andras AA, Predescu AM, Pantilimon C, Pica A, Predescu C. Recycled polypropylene improved with thermoplastic elastomers. Int J Polym Sci. 2017;7–8:1–10.CrossRefGoogle Scholar
  31. 31.
    Strapasson R, Amico SC, Pereira MFR, Sydenstricker THD. Tensile and impact behavior of polypropylene/low density polyethylene blends. Polym Test. 2005;24:468–73.CrossRefGoogle Scholar
  32. 32.
    Frone AN, Panaitescu DM, Chiulan I, Gabor AR, Nicolae CA, Oprea M, Ghiurea M, Gavrilescu D, Puitel AC. Thermal and mechanical behavior of biodegradable polyester films containing cellulose nanofibers. J Therm Anal Calorim. 2019.
  33. 33.
    Panaitescu DM, Nicolae CA, Vuluga Z, Vitelaru C, Sanporean GC, Zaharia C, Florea D, Vasilievici G. Influence of hemp fibers with modified surface on polypropylene composites. J Ind Eng Chem. 2016;37:137–46.CrossRefGoogle Scholar
  34. 34.
    Pawlak A, Galeski A. Crystallization polypropylene. In: Karger-Kocsis J, Bárány T, editors. Polypropylene handbook: morphology, blends and composites. New York: Springer; 2019.Google Scholar
  35. 35.
    Kang J, Yang F, Wu T, Li H, Liu D, Cao Y, Xiang M. Investigation of the stereodefect distribution and conformational behavior of isotactic polypropylene polymerized with different Ziegler–Natta catalysts. J Appl Polym Sci. 2012;125:3076.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  • Sergiu Alexandru Stoian
    • 1
    • 2
  • Augusta Raluca Gabor
    • 1
  • Ana-Maria Albu
    • 2
  • Cristian Andi Nicolae
    • 1
  • Valentin Raditoiu
    • 1
  • Denis Mihaela Panaitescu
    • 1
    Email author
  1. 1.National Institute for Research & Development in Chemistry and Petrochemistry ICECHIMBucharestRomania
  2. 2.Department of Bioresources and Polymer ScienceUniversity POLITEHNICA BucharestBucharestRomania

Personalised recommendations