(347f) Understanding Barrier Properties of Plastics for Packaging Applications: A Comprehensive Approach to Polymer Performance

Moisture, carbon dioxide, and oxygen in air produce spoilage of food at a fast rate. Packaging, based on plastics, is designed to increase the shelf life by creating a barrier between food and air. Packaging also protects food from other contaminants including bacteria. Plastic packaging has become widespread and has seen overtime high success due to the low cost to transport products compared to those packaged with metals or ceramics. Plastics are light weight and have high performance for multiple applications including protecting food and innumerable merchandise. Plastics, including petro-based or bio-based, are all different and many of them make excellent light weight, transparent, and though packaging, while others are opaque and strong and/or rigid. Different plastics present different barrier properties and are selective towards moisture, oxygen, or carbon dioxide. Packaging is normally layered due to the different properties of plastics. Measuring and understanding the properties of plastics is essential. Molecular weight, molecular orientation, chemistry, and crystallinity are all essential to understand the overall phenomenon. We will discuss a correlation between these variables with the barrier performance of various plastics including bio-based polymers. It has been found that bio-based polymers can perform as well as petro-based polymers based on barrier properties. Barrier properties of polymers is a complex phenomenon that depends not only on the crystallinity, but on the chemical structure and properties of the polymers. Layering of polymers is an excellent technical recourse to improve the barrier properties of plastics.

Acknowledgements:

This research is financially supported by the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), Canada/University of Guelph - Bioeconomy for Industrial Uses Research Program Theme (Project # 030255); the Natural Sciences and Engineering Research Council (NSERC), Canada−Discovery Grants (Project # 401111 and 400320); and the Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research, Innovation and Science (MRIS) (Project # 052665 and #052644).