Blends of PP/PE co‐octene for modified atmosphere packaging applications

Abstract

The aim of this work was to obtain films of polypropylene (PP)/polyethylene co-octene (POE) blends and study the influence of their composition and mixing conditions on final morphology and ultimate properties (thermal, mechanical, oxygen and water vapour transmission rates).Scanning electron microscopy showed segregation of POE domains in the PP matrix. Thermal analysis indicated that the addition of POE modified neither the melting temperature nor the crystallinity of PP in the pressed films. It was found that permeabilities of films were mainly related to POE content rather than morphological features. For the maximum POE concentration used (40%), the oxygen permeability increased up to~100% from that of neat PP. A similar trend was found for water vapour permeability. Rigidity of blends dropped significantly with the addition of POE although their ductility slightly increased when compared to pure PP. No significant effect of blend preparation conditions on these properties was found. Mechanical and permeability characteristics of films make them very attractive to be used for MAP of fresh produce such as apple, blueberry and mushroom.

Modified Atmosphere Packaging, for Minimally Processed Foods

“…Most pure polymers are much more permeable to CO 2 than O 2 , with b values ranging from 2.4 to as high as 10.2 (Exama et al, 1993). However, certain polymer blends or additives have been found to have a large effect on P O 2 (Acosta et al, 2011;Gorney, 2003). Therefore, by controlling polymer composition, films with high gas permeabilities and b values close to unity are available, and these have been shown to be very effective in MAP produce systems (Zhu et al, 2002).…”