Luke Barnetta,b
aInstitute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerddan, Aberystwyth, Ceredigion, SY23 3EE, UK
bPlant Science Laboratory, Cranfield University, Bedfordshire, MK43 0AL, UK
There is an increasing need to find an alternative resource to make plastic films for the food packaging industry, that is more sustainable than crude oil. Sodium alginate (SA) has film forming capabilities which could provide a biodegradable solution to this problem. However, a plasticiser must be included to ensure adequate water resistance properties for the length of a ready to eat product’s shelf life. With plasticiser inclusion into SA films being a relatively unexplored field, this has presented an opportunity to characterize the properties exhibited when different plasticisers are included in a SA film. After the creation of a cast moulding method coupled with oven drying for film formation, films with different physical properties could be created when a plasticiser and its concentration was varied. Various plasticisers were trailed at differing concentrations including carbohydrates, polyols, oils, and cellulose nanocrystals and nanofibers. Each plasticiser produced its own properties once the films had dried. The study defined what plasticiser, and concentrations of more suitable plasticisers, produce physical properties similar to that of plastic films currently used in the food packaging industry. Following this, the exhibited properties of films were characterised when the most suitable plasticisers were incorporated into a film in combination with each other. The plasticiser resultantly produced films with more flexible properties when polyols were included. A higher tensile strength was produced by films containing cellulose. Carbohydrates seem to produce a clearer film, ideal for product viewing. Plasticiser concentration is important in defining how much a property is exhibited.