Preparation and Characterization of Methylcellulose Derivatives from Cellulosic Wastes

Cellulosic wastes from El-Nasr Co. for Intermediate Chemicals are used as a starting material for the preparation of methylcellulose with tailored properties. The wastes are first purified, followed by alkali ageing for different intervals of time. This is done to control the molecular weight of the cellulose molecules, thereby obtaining cellulosics with different degrees of polymerization (DP). These samples along with the original purified cellulose are methylated under similar conditions and the obtained methylcellulose samples are examined for solubility, degree of substitution (DS) and rheological properties. The results obtained from these investigations are summarized as follows. It is found that the DP of the starting cellulose progressively decreases by prolonging the duration of alkali ageing, while the carboxyl content increases. The DS of the methyl groups increases as the DP of the starting substrate decreases. The rheological properties as well as the apparent viscosity at various rates of shear for the prepared derivatives are thoroughly investigated.