Catalyst-Free Conversion of Alkali Cellulose to Fine Carboxymethyl Cellulose at Mild Conditions

Cellulose fibers were converted into a valuable cellulose derivative, which is easily marketable with additional values. Alkali cellulose and carboxymethyl cellulose (CMC) is the most important cellulose derivatives. Alpha-cellulose was furnished as raw material for production of CMC, which is obtained from short cotton fibers, then purified. Alpha-cellulose is available in the international market. Preparation of carboxymethyl cellulose was conducted using sodium hydroxide solution in sequential reactions with monochloroacetate (MCA) at desired condition. Alkali cellulose has been successfully synthesized in a batch reactor with degree of substitution (DS) of 0.15 to 0.7 and excellent purity of 99.3% at pH 7. The maximum degree of substitution of 0.7 was defined with 40% MCA and 30% NaOH. The reaction temperature was controlled and the purity of the product was examined through the course of reactions. The samples of CMC were examined by scanning electron microscope and FTIR techniques. A comparison study with CMC available in the international market has been conducted. The obtained results for the synthesized CMC with more than 99% purity were promising. The synthesized CMC was easily dissolved in water. The obtained product is absolutely recommended for pharmaceutical applications and as food additives.