In situ modifications to bacterial cellulose with the water insoluble polymer poly-3-hydroxybutyrate.

Bacterial cellulose is a pure, highly crystalline form of cellulose produced from the bacteria Gluconacetobacter xylinus that has become of increasing interest in materials science due to its nanofibrillar structure, ideal for incorporation into other materials as a reinforcing material. The morphology and properties of bacterial cellulose can be altered by including additives not specifically required for growth of the bacteria in liquid media. The bioplastic poly-3-hydroxybutyrate (PHB), along with hydroxypropylmethyl cellulose (HPMC) and Tween 80 were selected and added to the growth media at different concentrations to examine their impact on the resulting cellulose, leading to changes in yield, crystallinity and morphology. The crystallinity index of the nanofibrils was found to vary greatly when using these different methods to calculate it from XRD data, indicating that particular care must be taken when comparing crystallinity results reported in the literature. PHB was able to be incorporated into the bacterial cellulose fibrils during production, increasing the potential for favourable interactions of the bacterial cellulose microfibrils with a neat PHB matrix with the aim of making a fully degradable nanocomposite system.