Send to

Choose Destination
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2008 Nov;25(11):1409-15. doi: 10.1080/02652030802162747.

Diffusion behaviour of additives in polypropylene in correlation with polymer properties.

Author information

US Food and Drug Administration, Centre for Food Safety & Applied Nutrition (CFSAN), College Park, MD, USA.


The migration behaviour of polymer additives in 17 polypropylene (PP) samples is described. These samples cover the major types of PP used in food packaging. The diffusion coefficients of additives with relatively small molecular masses, M(r) = 136 (limonene), as well as the migration of typical antioxidants used in PP up to M(r) = 1178 (IRGANOX 1010), were measured at different temperatures. In addition, the diffusion data and percentages of xylene-soluble fractions were correlated. This enables a prediction of the migration behaviour of a PP sample by testing its 'isotactic index' with xylene. The results clearly indicate that PP can be subdivided, from the migration point of view, into the monophasic homopolymer (h-PP), the monophasic random copolymer (r-PP), and the heterophasic copolymer (heco-PP). The diffusion coefficients for r-PP are at least one order of magnitude higher than those of h-PP and comparable with the values for heco-PP. Upper limits for the diffusion values can be calculated based on the safety margin required by consumer protection laws.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center