engleski

Polymer films for food packaging modified by zeolite and nanoclay

Polymer packaging materials play an important role in the food industry. It gives food greater safety assurance from microorganisms, chemical and mechanical changes. Low density polyethylene (PE- LD) is the most commonly used polymer for packaging with its advantages of being inert, permeable to gases and impermeable to water. In the last decade, there has been considerable focus, both academic and industrial, on the introduction of polymer nanocomposites in food packaging. They exhibit dramatic enhancement of a large number of physical properties which include mechanical and barrier properties. The primary benefits of nanoclays are flame retardant synergy, improved balance of stiffness and toughness, and barrier properties. Nanoparticles are nowadays used in the production of food packaging, which improves the barrier properties and/or reduces the concentration of the substances that can affect the quality and safety of food. To improve the permeability of the film, zeolite– polymer composite films are produced. The solid– low density polyethylene composite films were prepared by extrusion of polyethylene beads with zeolite particles and nanoclay. PE-LD samples containing two types of filler in concentrations of 2-10 wt % (zeolite T-MAZ 7 and nanoclay Cloisite 20A) were extruded at speed of 100 rpm. The mechanical properties of composites were tested and thermal stability was determined. The barrier characteristics of the studied samples i.e. oxygen, carbon dioxide and nitrogen permeance was performed. Highly impermeable patches are obtained in PE- LD/Z/C due to embedding micronized zeolite and nanoclay. It is presumed that in quoted samples the optimal concentration of inorganic particle is present resulting in improved thermal stability, mechanical properties and reduced permeability.

Polymer films; PE-LD; composites; zeolite; nanoclay

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