UTILIZATION OF RICE STRAW IN THE PRODUCTION OF SOME CELLULOSIC DERIVATIVES

Abstract

Egypt produces around 4 million tons of rice straw / annually. Fields must be cleaned from straw to make way for the next crop. Soil incorporation and field burning have been the major practice for removing rice straw. Field burning damage the land by killing useful microorganisms in the soil and incorporation in the soil is slower, more expensive and may promote rice diseases. The smoke from the rice straw combustions is also a potential health hazard for humans because it could give rise to asthma and cancer. Cellulosic compounds are the most important renewable natural resources on earth. Cellulose is the main component of plant cell walls, and the basic building block for many textiles and for paper. Cellulose is a hard crystalline material fibrous enough to use as paper, textiles, clothes, strings, sanitary goods, etc.. Cellulose is insoluble in water and most common solvents. Bonding between the individual chains prevents it from being broken by mild chemicals or water, and makes it resistant to enzyme decomposition. Hydrogen bonds, which give cellulose stability, are broken down through pretreatment methods by chemical reactions that take place in hydroxyl groups and glucosidic linkage of cellulose molecule. Cellulose has the ability to functionalize chemically to provide cellulose derivatives, such as cellulose esters and ethers which have important applications in our daily life such as in textiles, pharmaceuticals, food, and packaging industries. It is directly linked to the paper industry. Cellulose derivatives are further used as coatings, laminations, optical films and absorbents. Ionic liquids (IL) possess not only a high chemical and thermal stability, nonflammability and a negligible vapor pressure, but also the recycling of these solvents is comparably easy. Recently, certain ILs have been applied as green solvents which would dissolve cellulose and function