ABSTRACT
Cellulose has been popularly used as a material for centuries in all kinds of practical applications. It is the world’s most abundant renewable and biodegradable polymer. This chapter discusses two major groups of cellulose derivatives which are of significant importance in medical uses, namely, cellulose ester and cellulose ether. Cellulose is a polydisperse, linear syndiotactic polymer. Its basic monomeric unit is d-glucose, which links successively through a glycosidic linkage in the ß-configuration between carbon 1 and carbon 4 of adjacent units to form long chain 1,4-glucans. The chemical reactivity of cellulose is determined to a large extent by the supermolecular structure of its solid state. Cellulose contains 31.48% by weight of hydroxyl groups, which play the influential role in the preparation of cellulose derivatives. Microcrystalline cellulose is purified, partially depolymerized cellulose prepared by treating high quality cellulose with hydrochloric acid to the point of leveling off degree of polymerization.
