Comparative study of degradation of PP modified with organic pro-degradant subjected to natural and artificial ageing

Document Type : Original research


1 UFRGS (Laboratory of Polymeric Materials, Department of Materials Engineering, Federal University of Rio Grande do Sul, 91540-000, Porto Alegre, Rio Grande do Sul, Brazil)

2 UNIVILLE (Engineering of Process Program, University of Joinville Region, Campus Universitário, s/n, Bairro, Bom Retiro, 89.201-972, Joinville, Santa Catarina, Brazil)


In abiotic degradation the action of light radiation is one of the most important parameters, because polymers undergo degradation due to the action of light (natural or artificial). The aim of this study was to investigate the degradation rate for samples of polypropylene (PP) modified with an organic pro-degradant submitted to ageing in a natural environment and to accelerated ageing test. The degradation behavior of the samples exposed to the ageing processes was evaluated through changes in the degree of crystallinity (Xc ), surface morphology (Scanning Electron Microscopy) and molecular weight. The results indicated that for the modified polypropylene samples natural ageing led to a 42.3% reduction in the molecular weight and the surface morphology showed evidence of erosion. In the accelerated ageing process the UV radiation was stronger, which led to a 94.3% increase in the degree of crystallinity and micro-voids were present on the surface of the modified polypropylene.


Main Subjects

  1. Morancho JM, Ramis X, Fernández X, Cadenato A, Salla JM, Vallés A, Contat L, Ribes A (2006). Calorimetric and thermogravimetric studies of UV-irradiated polypropylene/starch-based materials aged in soil. Polym Degrad Stabil 91: 44-51
  2. Santos PA, Oliveira MN, Paoli MA, Freitas VG (2013) Avaliação do efeito pró-oxidante no PP, em blendas com PHB. Polímeros, 23 (3): 432-439
  3. Thornberg SM, Bernstein R, Irwin AN, Derzon DK, Klamo SB, Clough RL (2007) The genesis of CO2 and CO in the thermooxidative degradation of polypropylene. Polym Degrad Stabil 92: 94- 102
  4. Marek A, Kaprálková L, Schmidt P, Pfleger J, Humlícek J, Pospísil J, Pilar J (2006) Spatial resolution of degradation in stabilized polystyrene and polypropylene plaques exposed to accelerated photodegradation or heat aging. Polym Degrad Stabil 91: 444-458
  5. Fechine GJM, Demarquette NR, Freitas CA, Fernandes LL (2012) Estudo do efeito do tipo de polipropileno na fotodegradação da blenda polipropileno/poliestireno de alto impacto. Polímeros 22: 61-68
  6. Lucas N, Bienaime C, Belloy C, Queneudec M, Silvestre F, Nava-Saucedo JE (2008) Polymer biodegradation: Mechanisms and estimation techniques – A review. Chemosphere 73: 429-442
  7. Geburting A, Wachetendorf V (2010) Determination of the spectral sensitivity and temperature dependence of polypropylene crack formation caused by UV-irradiation. Polym Degrad Stabil 95: 2118-2123
  8. Rabello MR, White JR (1997) Crystallization and melting behaviour of photodegraded polypropylene - I. Chemi-crystallization. Polym 38: 6379-6387
  9. Rabello MR, White JR (1997) Fotodegradação do polipropileno. Um processo essencialmente heterogêneo. Polímeros 7: 47-57
  10. Qui W, Endo T, Hirotsu T (2005) A novel technique for preparing of maleic anhydride grafted polyolefins. Eur Polym J 41: 1979-1984
  11. Yakimets I, Lai D, Guigon M (2004) Effect of photo-oxidation cracks on behaviour of thick polypropylene samples. Polym Degrad Stabil 86: 59-67
  12. Bertin D, Leblanc M, Marque SRA, Siri D (2010) Polypropylene degradation: Theoretical and experimental investigations. Polym Degrad Stabil 95: 782-791
  13. Muthukumar T, Aravinthan A, Mukesh D (2010) Effect of environment on the degradation of starch and pro-oxidant blended polyolefins. Polym Degrad Stabil 95: 1988-1993
  14. Ito M, Nagai K (2008) Degradation issues of polymer materials used in railway field. Polym Degrad Stabil 93: 1723-1735
  15. Jansen JFGA, Gijsman P (2008) Process for improving the biodegradability of a polymer. WO 2008/006492 A1 16.
  16. Lewis FD, Lauterbach RT, Heine HG, Hartmann W (1975). Photochemical α cleavage of benzoin derivatives. Polar transition states for free-radical formation. J Am Chem Soc 97: 1519-1525
  17. American society for testing and materials (2013) Standard practice for outdoor weathering of plastics. ASTM D1435-13
  18. American Society for Testing and Materials (2010) Standard practice for exposing nonmetallic materials in accelerated test devices that use laboratory light sources. ASTM G151-10
  19. American Society for Testing and Materials (2006) Standard practice for operating fluorescent light apparatus for UV exposure of nonmetallic materials. ASTM G154-06
  20. Fu Q, Bing N, Wang K, Zhang Q, Du R (2005) Tensile properties in the oriented blends of highdensity polyethylene and isotactic polypropylene obtained by dynamic packing injection molding. Polym 46: 3190-3198
  21. Bandrupt J, Immeergut, EH (2009) Polymer Handbook. 2nd Ed. Wiley – Interscience publication, New York
  22. Chiellini E, Corti A, D’Antone S, Baciu R (2006) Oxo-biodegradable carbon backbone polymers – Oxidative degradation of polyethylene under accelerated test conditions. Polym Degrad Stabil 91: 2739-2747
  23. De Paoli MA (2009) Degradação e estabilização de polímeros. São Paulo, Artliber
  24. Girois S, Audouin L, Verdu J, Delprat P, Marot G (2006) Molecular weight changes during the photooxidation of isotactic polypropylene. Polym Degrad Stabil 51: 125-132
  25. Vogt NB, Kleppe EA (2009) Oxo-biodegradable polyolefins show continued and increased thermal oxidative degradation after exposure to light. Polym Degrad Stabil 94: 659-663
  26. Rivaton A, Gardette JL, Mailhot B, Therrlas SM (2005) Basic aspects of polymer degradation. Macromol Symp 225: 129-146
  27. Agnelli J AM, Chinelatto MA (1992) Degradação de polipropileno: Aspectos teóricos e recentes avançados em sua estabilização. Polímeros: Ciência e Tecnologia 2: 27- 31
  28. Tidjani A, Watanabe Y (1995) Comparison of polyethylene hydroperoxide decomposition under natural and accelerated conditions. Polym Degrad Stabil 49: 299-304
  29. Tidjani A (2000) Comparison of formation of oxidation products during photo-oxidation of linear low density polyethylene under different natural and accelerated weathering conditions. Polym Degrad Stabil, 68: 465-469