Effect of Organic Modifier Types on the Physical–Mechanical Properties and Overall Migration of Post-Consumer Polypropylene/Clay Nanocomposites for Food Packaging

Abstract

The deterioration of the physical–mechanical properties and loss of the chemical safety of plastics after consumption are topics of concern for food packaging applications. Incorporating nanoclays is an alternative to improve the performance of recycled plastics. However, properties and overall migration from polymer/clay nanocomposites to food require to be evaluated case-by-case. This work aimed to investigate the effect of organic modifier types of clays on the structural, thermal and mechanical properties and the overall migration of nanocomposites based on 50/50 virgin and recycled post-consumer polypropylene blend (VPP/RPP) and organoclays for food packaging applications. The clay with the most hydrophobic organic modifier caused higher thermal stability of the nanocomposites and greater intercalation of polypropylene between clay mineral layers but increased the overall migration to a fatty food simulant. This migration value was higher from the 50/50 VPP/RPP film than from VPP. Nonetheless, clays reduced the migration and even more when the clay had greater hydrophilicity because of lower interactions between the nanocomposite and the fatty simulant. Conversely, nanocomposites and VPP/RPP control films exhibited low migration values in the acid and non-acid food simulants. Regarding tensile parameters, elongation at break values of PP film significantly increased with RPP addition, but the incorporation of organoclays reduced its ductility to values closer to the VPP.

Valorization of Polypropylene Waste in the Production of New Materials with Adequate Mechanical and Thermal Properties for Environmental Protection

“…The unfilled PPW showed a T m of 164.6 °C, similar to the value reported in the literature for other PP wastes [ 12 ]. Two melting endothermic peaks (T m ) were observed for the PPW composites, one related to the melting of high density polyethylene (HDPE) at T m1 ~129 °C [ 38 , 55 ], and another one to the melting of PP at T m2 ~164 °C ( Figure 7 a). Other authors also reported the additional melting peak ascribed to HDPE during the heating process [ 27 , 56 , 57 , 58 ].…”

“…Belviso et al [ 26 ] observed that recycled PP waste with a natural clay mineral and zeolite showed a decrease in the elongation of composites, due to the filler’s agglomeration leading to the weakening of interfacial interactions. Other researchers reported that the addition of n-clays improved the properties of recycled PP composites used for the treatment of textile dye waste water [ 37 ] or in food packaging [ 38 ].…”

Migración Química Desde Envases Fabricados Con Polipropileno Hacia Alimentos Grasos

“…Por estas propiedades hacen que el PP sea un polímero muy comercial comparado con otros polímeros de similares características; además, es de fácil procesamiento inicial y también en posconsumo haciéndolo ideal para múltiples aplicaciones en diferentes sectores de la industria (Velásquez et al, 2021). El PP se clasifica en homopolímeros y copolímeros, que generalmente son utilizados para fabricar envases que van a estar en contacto directo con alimentos, debido a que son químicamente inertes, termosellables y proporcionan una excelente barrera contra el agua (Hernández et al, 2001).…”

Enhancing Mechanical Properties of Graft-Type Nanocomposites Using Organically Modified SiO2 and Polypropylene Containing Reactive Methoxy Groups

“…Polypropylene (PP), one of the most abundant thermoplastics, has been employed for fabricating polymer nanocomposites using a wide variety of nanofillers [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. The hydrophobicity and chemical innerness of PP make uniform dispersion of nanoparticles challenging, for which various strategies have been reported.…”