Influence of Drying Temperature on Tensile and Bursting Strength of Bacterial Cellulose Biofilm

摘要

The article presents an experimental study of mechanical properties of cellulose biofilm produced by bacterial fermentation process. Naturally derived biomaterial has great current and potential applications therefore the conditions of material preparation as well as control and prediction of mechanical properties is still a relevant issue. Bacterial cellulose was obtained as a secondary product from Kombucha drink. Presented technique for material preparation and drying is particularly simple and easy to access. The influence of drying temperature (25?°C, 50?°C and 75?°C) on the sample size (thickness and planar dimensions) and mechanical properties (tensile and bursting strength) of cellulose biofilm has been evaluated. It was estimated that during drying biofilm specimens lost up to 92?% of weight and up to 87?% of thickness therefore planar specimen dimensions varied insignificantly. The study showed that the drying temperature is important for optimum strength properties of bacterial cellulose biofilm. The maximum tensile strength (27.91?MPa) was recorded for the samples dried at temperature of 25?°C, when the moisture from the biomaterial is removed gradually and good deformation properties are ensured (respectively tensile extension 18.8?%). Under higher drying temperature biomaterial shows lower values of tensile strength and higher values of bursting strength. The maximum bursting strength (57.2?MPa) was recorded for samples dried at 75?°C when punch displacement changes were insignificant for all tested samples (from 17.8?mm to 21.7?mm).