2.4.3. Moisture uptakeMoisture uptake was measured as described in our previousstudy [32]. Prior to testing all specimens were cut to a square pieceof 2.0 cm × 2.0 cm and conditioned using anhydrous calcium sulphate at 0% RH for 48 h. The films were accurately weighed to give the dried film (Wi). After weighing, they were conditioned at23±1◦C in a desiccator containing potassium sulphate saturated solution to ensure a relative humidity of 97%. The samples were removed from the desiccator after 48 h and weighed (W1). Themoisture up take values of the samples were calculated using the following equation