Macromolecular non-releasing additives for safer food packaging: application to ethylene/α-olefins and propylene based polymers

Document Type : Original research


1 Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via E. Bassini 15, 20133 Milano (Italy)

2 Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via De Marini 6, 16149 Genova (Italy)

3 Dipartimento di Chimica ‘Ugo Schiff’, Università di Firenze, via della Lastruccia 13, 50019 Sesto Fiorentino (FI) (Italy)

4 Department of Food, Environmental and Nutritional Sciences DeFENS, University of Milan, Via Celoria 2, 20133, Milano (Italy)


Some innovative solutions are proposed to the problem of the unavoidable physical migration of antioxidants from plastic films for packaging, in order to minimize the consequent undesirable effect of food contamination. In previous exploratory tests, phenolic antioxidant co-units were achieved and incorporated into polyethylene chain and now the work is extended to create new families of polymeric additives properly designed for specific material. An effective route was designed to synthesize the functionalized comonomer, analogues of commercial 2,6-t-butyl-4-methoxy-phenol (BHA), containing eight methylene units as spacer between the aromatic ring and the polymerizable olefinic double bond (C8). Ethylene/1-hexene/C8 terpolymers, with 1-hexene concentration in the typical range found in commercial polyethylene grades, and propylene/C8 copolymers with microstructure similar to those of commercial packaging polypropylenes were produced. A careful 13C NMR study was conducted for the precise determination of the functionalized comonomer content on all terpolymer and copolymer samples. The samples melt blended with additive-free commercial LDPE and PP matrices, individually, were analyzed in terms of thermal and thermo-oxidative stability and compared with LDPE and PP films containing the traditional BHA additive analogue. The results demonstrate that, in either way, the polymeric additives exert a very positive effect on the degradation temperature of the polymeric matrices, retarding the thermo-oxidative sequence of reaction.


Main Subjects

1. Al-Malaika S (1989) Effects of Antioxidants and Stabilization. In:Allen G, Bevington JC (eds), Eastwood GC, Ledwith A, Russo S, Sigwalt P (vol eds) Comprehensive Polymer Science. Pergamon, New York, Vol 6:539-576
2. Kuczowsky JA, Gillick JG (1984) Polymer-bound antioxidants. Rubber Chem Technol 57:621-651
3. Curcio M, Puoci F, Iemma F, Parisi OI, Cirillo G, Spizzeri UG, Pucci N (2009) Covalent Insertion of Antioxidant Molecules on Chitosan by a Free Radical Grafting Procedure. J Agric Food Chem 57:5933-5938
4. Sacchi MC, Cogliati C, Losio S, Costa G, Stagnaro P, Menichetti S, Viglianisi C (2007) Macromolecular non-releasing additives for commercial polyolefins. Macromol Symp 260:21-26
5. Menichetti S, Viglianisi C, Liguori F, Cogliati C, Boragno L, Stagnaro P, Losio S, Sacchi MC (2008) Ethylene based copolymers with tunable content of polymerizable hindered phenols as non-releasing macromolecular additives. J Polym Sci, Part A:Polym Chem 46:6393-6406
6. Boragno L, Stagnaro P, Losio S, Sacchi MC, Menichetti S, Viglianisi C, Piergiovanni L, Limbo S (2012) LDPE-based blends and films stabilized with non-releasing polymeric antioxidants for safer food packaging. J Appl Polym Sci 124:3912-3920
7. Sacchi MC, Losio S, Stagnaro P, Menichetti S, Viglianisi C (2013) Design and synthesis of olefin copolymers with tunable amounts of comonomers bearing stabilizing functionalities. Macromol React Eng 7:84-90
8. Wilén CE, Nasman JH (1994) Polar activation in copolymerization of propylene and 6-tert-butyl- 2-(1,1-dimethylhept-6-enyl)-4-methylphenol over a racemic [1,1’-(dimethylsilylene)bis(h5- 4,5,6,7-tetrahydro-1-indenyl)]zirconium dichloride/methylaluminoxane catalyst system. Macromolecules 27:4051-4057
9. Wilén CE, Nasman JH (1996) Copolymerization of ethylene and 6-tert-butyl-2-(1, 1-dimethylhept- 6-enyl)-4-methylphenol over three different metallocene-aluminoxane catalyst systems. Macromolecules 29:8569-8575
10. Randall JC (1975) Carbon-13 nuclear magnetic resonance quantitative measurements of monomer sequence distributions in hydrogenated polybutadienes. J Polym Sci, Polym Phys Ed 13:1975-1990
11. Hsieh ET, Randall JC (1982) Monomer sequence distributions in ethylene 1-hexene copolymers. Macromolecules 15:1402-1406
12. Cheng HN (1991) Comonomer sequence distribution in ethylene/1-hexene copolymers. Polym Bull 26:325-332
13. Xu G, Ruckenstein E (1998) Ethylene copolymerization with 1-octene using a 2-methylbenz[e]indenyl-based ansa-monocyclopentadienylamido complex and methylaluminoxanes catalyst. Macromolecules 3 1 : 4 7 2 4 - 4 7 2 9
14. Qiu X, Redwine D, Gobbi G, Nuamthanom A, Rinaldi PL (2007) Improved peak assignments for the 13C- NMR spectra of poly (ethylene-co-1- octene)s. Macromolecules 40:6879-6884
15. Kimura K, Yuasa S, Maru Y (1984) C-13 nuclear magnetic-resonance study of ethylene 1-octene and ethylene 4-methyl-1-pentene copolymers. Polymer 25:441-44
16. Quijada R, Guevara JL, Galland GB, Rabagliati FM, Lopez-Majada JM (2005) Synthesis and properties coming from the copolymerization of propene with alpha-olefins using different metallocene catalysts. Polymer 46:1567-1574
17. Carvill A, Zetta L, Zannoni G, Sacchi MC (1998) ansa-zirconocene-catalyzed solution polymerization of propene:influence of polymerization conditions on the unsaturated chain-end groups. Macromolecules 31:3783- 3789
18. Tochàĉek J (2004) Effect of secondary structure on physical behaviour and performance of hindered phenolic antioxidants in polypropylene. Polym Degrad Stabil 86:385-389
19. Wen Z, Hu X, Shen D (1988) The FTIR studies of photo-oxidative degradation of polypropylene. Chinese J Polym Sci 6:285-288
20. Rabello MS, White JR (1997) The role of physical structure and morphology in the photodegradation behaviour of polypropylene. Polym Degrad Stabil 56:55-73
  • Receive Date: 21 December 2012
  • Revise Date: 03 July 2013
  • Accept Date: 06 July 2013
  • First Publish Date: 01 January 2014