Rectangular specimens having 5.0 cm length, 1.0 cm breadth, and 0.66 cm thickness were cut from the composites. Initially, samples were weighed, tied with thread, and hanged over the steam bath for duration of 0–150 h. Relative humidity of the system was measured by hygrometer and found 100%. At a regular interval of time, the specimens were taken out from the steam. The steam (water molecules) from the surface was removed by filter paper and weighed. Loss of water due to evaporation was compensated by continuous addition of water. All the measurements were carried out within 30–40 s. The mole of water uptake ("Q" _"t" ) by 100 g of polymer was plotted against square root of time and was calculated from eq. (1).