Oxygen barrier properties of polyketone/EVOH blend films and their resistance to moisture

Abstract

Polyketone (PK) has excellent chemical and mechanical properties, but its use in food packaging is limited due to its oxygen barrier properties being insufficient for high‐barrier film applications. To improve its oxygen barrier properties, PK has been blended with ethylene vinyl alcohol copolymer (EVOH), which is one of the highest oxygen barrier polymers in use today. The oxygen barrier properties under both dry and humid conditions, as well as the mechanical properties of PK/EVOH blend films were investigated in this study. These novel PK/EVOH blend films exhibited unusually low oxygen permeability values from 0.3 to 0.16 cc 20 μm m−2 day−1 atm−1 with increasing EVOH content from 30 to 70 wt%, which are even lower than those of the ideal laminar model that expresses the theoretical minimum permeability values attainable for blended barrier films. These high oxygen barrier properties of PK/EVOH blend films can conceivably be attributed to the combination of two dominant effects: a tortuous diffusion path through the EVOH domains in the PK matrix and hydrogen bonding interactions between PK and EVOH. Furthermore, in high‐humidity environments with retorting, the PK/EVOH blend films exhibited superior resistance to moisture over EVOH. Immediately after the retorting test, the oxygen permeability of the high‐barrier PK/EVOH blend films with an EVOH content of 30–40 wt% increased by less than 3× the pre‐retorting value, as opposed to 74× for EVOH. In addition, PK/EVOH blend films displayed superior stretching characteristics, with a breaking strain of over 300%, which are valuable for flexible packaging applications.

Graphene oxide as a multi-functional additive for compatilizer, enhancer, and barrier in ethylene vinyl alcohol copolymer/aramid pulp composites

“…Besides, the EVOH matrix can also be strengthened with inorganic llers, such as ber and graphene, which can decrease the costs of products and improve dramatically the comprehensive properties. 12 Aramid pulp (AP) is brillated by poly-p-phenylene terephthalamide (PPTA), known by its trade-name Kevlar, possessing high specic modulus and specic strength, outstanding thermal stability, and lightweight, resulting in a variety of applications in aerospace, military, automotive industry and sports goods. 13,14 Therefore, aramid pulp can be considered an ideal ller to reinforce polyolen matrix due to its prominent mechanical and thermal properties.…”

“…Besides, the EVOH matrix can also be strengthened with inorganic fillers, such as fiber and graphene, which can decrease the costs of products and improve dramatically the comprehensive properties. 12 …”

Activation of a Palladium-Based Catalyst by Hexafluoroisopropanol for Polyketone Synthesis via Homogeneous Solution Polymerization

“…Recently, both academia and industry have paid close attention to polyketone (PK), a product of the copolymerization of alkenes and carbon monoxide (CO). − When producing PK, CO is used directly in a one-step polymerization without intermediate steps, like the synthesis of ethene or propene. , Because of its superior mechanical properties, chemical resistance, and gas barrier characteristics, PK is a widely used engineering plastic. − Furthermore, because of the carbonyl structures on its molecular backbone, it has photodegradation characteristics …”

Microwave-Induced Grafting of Maleic Anhydride onto the Surface of a Polypropylene Film for High Adhesion to Polyamide 6

“…Barely one material can suffice all of the requirements. A multilayer packaging technique combines the benefits of multiple materials in terms of their mechanical, moisture and oxygen barrier, and other functional properties through coextrusion and lamination. , Polyethylene and polypropylene (PP) materials are widely used in the inner and outer layers in packaging to provide mechanical support, safe contact with food, and moisture guard. , Polyamide (PA) and ethylene vinyl alcohol copolymer (EVOH) materials are used in the intermediate layer as oxygen barriers. A tie layer is typically needed between layers with materials of distinct polarities, e.g., PP and PA, to strengthen the adhesion and to maintain the mechanical integrity of the film. , …”

“…1,2 Polyethylene and polypropylene (PP) materials are widely used in the inner and outer layers in packaging to provide mechanical support, safe contact with food, and moisture guard. 3,4 Polyamide (PA) 5 and ethylene vinyl alcohol copolymer (EVOH) 6 materials are used in the intermediate layer as oxygen barriers. A tie layer is typically needed between layers with materials of distinct polarities, e.g., PP and PA, to strengthen the adhesion and to maintain the mechanical integrity of the film.…”