Abstract

• Dissolution of rice straw (RS) in an ionic liquid (IL), 1-butyl- 3-methylimidazolium acetate BMIMOAc was studied with regard to effects of size, amount of rice straw powder, dissolution time and dissolution temperature. Highest yield percent (76.65 %) of regenerated cellulose was achieved using 0.149 mm size and 0.2 g of rice straw powder. Effect of dissolution time (10, 30, 90 min) on the yield percent of regenerated cellulose showed that higher yield percentages of 78.08 % and 76.65 % were achieved for dissolution times of 90 min and 30 min respectively. Three dissolution temperatures were set for dissolution study and it was found that the shortest dissolution time (10 min) was observed at 160 ºC. Surface morphology of the regenerated cellulose samples showed amorphous and porous structure compared to highly organized fibril structure of raw rice straw powder. Amorphous structure of regenerated cellulose samples were also confirmed by FT IR spectral data. The appearance of amorphous band around 900cm-1 of cellulose was observed in regenerated cellulose indicating the reduction of crystallinity. Crystalline peak of cellulose at (101) plane at 2 value of 22º was clearly observed in raw rice straw powder whereas the peak intensity decreased or absent in regenerated sample. By the optimization of the dissolution condition, 0.2 g of rice straw powder with 0.149 mm size was chosen for dissolution of rice strow at 120 ºC for 30 min.