Comparison of the Functional Barrier Properties of Chitosan Acetate Films with Conventionally Applied Polymers

Abstract

The current demand to cut back on the use of plastic materials has brought a major boost to the search for bio-based alternatives. Not only are plastic bags and primary food packaging under scrutiny here, but also those materials used as functional barriers to reduce, for example, the migration of mineral oil hydrocarbons (MOH) from recycled paper and board packaging. Most of the barriers now in use are synthetic, often have only moderate barrier functionalities and in addition reduce the environmentally-friendly character of cellulose-based materials. Against this background, bio-based polymers have been evaluated in terms of their functional barrier properties. Chitosan was found to be among the best performers in these materials. In this study, the behavior of a lab-made chitosan acetate film was compared with conventionally produced polymer films. The two-sided migration experiment described recently was used to determine the barrier properties of the tested materials. This not only allowed to test the intrinsic migration of the films and the permeation through them, but also to simulate real packaging situations by using a recycled paper as donor for MOH. The migrated fractions were determined using gas-chromatography-based techniques. While the conventionally produced polymer films showed only moderate barrier function, excellent results were seen for the biopolymer. It reduced the migration from the recycled paper to not detectable, singling it out as a good alternative to conventional materials.

Extensive Characterization of Alginate, Chitosan and Microfibrillated Cellulose Cast Films to Assess their Suitability as Barrier Coating for Paper and Board

“…Most studies investigating film formation use plasticizers to alter film properties [ 13 , 19 ]. Other studies focus on the solution concentration used to cast films and add surfactant [ 20 ] or investigate films containing additional starch [ 14 , 15 ] or acetate [ 21 ]. With these modifications again the direct assessment of different materials is not possible.…”

“…Films produced from this material show good barrier properties against air and oxygen [ 23 ]. These properties depend on multiple factors like the source and production of MFC [ 24 , 25 ], and the preparation of films and many studies focus on their improvement [ 20 , 21 ].…”