Cellulose fibre-reinforced biofoam for structural applications

Traditionally, polymers and macromolecular components used in foam industry are mostly derived from petroleum. The current transition to bioeconomy creates demand for use of more renewable feedstocks. Soybean oil is a vegetable oil, composed mainly of triglycerides, that is suitable material for foam production. In this study, acrylated epoxidized soybean oil and variable amounts of cellulose fibres were used in a production of bio-based foam. The developed macroporous bio-based architectures were characterized by several techniques, including porosity measurements, nanoindentation testing, scanning electron microscopy and thermogravimetric analysis. It was found that the introduction of cellulose fibres during the foaming process was necessary to create the three-dimensional polymer foams. Using cellulose fibres has potential as foam stabilizer because it obstructs drainage of liquid from the film region in these gas-oil interfaces while simultaneously acting as reinforcing agent in the polymer foam. The resulting bio-based macroporous polymers possessed a porosity of approximately 56%, and incorporation of cellulose fibres did not affected thermal behaviour. Scanning electron micrographs showed randomly oriented pores with irregular shapes and non-uniform pore size throughout the samples.