Optimisation of alginate films for sustainable food packaging applications

Plastic waste has a hugely detrimental impact on the environment and there is mounting pressure on industry to replace traditional polluting petrochemical polymers with sustainably-sourced polymers. Plastic film food packaging, while single-use, plays an important role in extending the shelf life of food and reducing food waste that is a significant contributor to greenhouse gases. While plastic films are typically made from recyclable polymers most plastic film food packaging is not recyclable due to food contamination and it is desirable to replace this film with compostable, sustainably-sourced alternatives. Alginate, sourced from seaweed, is a promising sustainable and compostable polymer, with the potential to replace oil-derived single use plastic films in food packaging applications. For food packaging applications, the alginate films must be compostable, have good mechanical properties, and have good gas and moisture barrier properties. However, several challenges must be overcome to improve the barrier and mechanical performance of alginate films for food packaging. This requires a fundamental scientific understanding of how the molecular interactions and physical processing conditions influence the material properties and performance. For example, the moisture barrier and mechanical properties can be improved through addition of plasticisers and/or filler particles, but care must be taken that this does not reduce the compostability. Current literature provides examples of how properties can be improved, however, a systematic approach based on molecular-level understanding is lacking and hampers progress. A molecular-level understanding of the interactions between alginate and plasticisers and the alginate-filler interface will enable intelligent design of alginate products, so that their properties and performance can be tuned, thus widening the range of applications of alginate films.

The aim of the project is to improve the performance of alginate films for food packaging. To accelerate the optimisation we will use simulation to gain insight into how the molecular interactions between alginate, plasticisers and filler particles affect the film's molecular structure. In order to achieve the aims of optimized properties and facile manufacturing, we will use experiment to investigate how the processing conditions, addition of plasticisers, and addition of fillers affect alginate film properties and performance. The project aims to deliver optimised alginate films for food packaging applications as well as a fundamental understanding on how additives and processing conditions impact the film properties.

Research students are also registered for the Postgraduate Certificate in Researcher Development (PGCert), which is a valuable supplementary qualification that develops a student’s skills, networks and career prospects. There will also be opportunity to gain teaching experience and to take part in the Department’s extensive outreach activities as part of the ReallySmallScience public engagement team.

Information about the host department can be found by visiting:

http://www.strath.ac.uk/engineering/chemicalprocessengineering

http://www.strath.ac.uk/courses/research/chemicalprocessengineering/