Modified carboxymethyl cellulose, their compositions and the uses thereof

A method for preparing mono-valent-di-valent (M+-M++)-carboxymethyl cellulose, the method comprising:

• (i) preparing an aqueous solution of (a) M++ chloride, M++ sulfate or M++ carbonate and (b) C2-C4 alcohol;
• (ii) adding sodium (M+)-carboxymethyl cellulose to step (i) and stirring the resultant for at least 30 minutes at an ambient temperature;
• (iii) filtering the resultant of step (ii) to obtain wet cake;
• (iv) stirring the wet cake of step (iii) in a hydroalcoholic solution for at least 30 minutes;
• (v) repeating the step (iv) for at least 3 times to obtain pure wet cake of M+-M++-carboxymethyl cellulose;
• (vi) drying the wet cake of step (v) on a fluid-bed dryer for at least 15-30 minutes at 50-70° C. to obtain dry M+-M++-carboxymethyl cellulose;
• and
• (vii) grinding the resultant of step (vi) to isolate dry powder of M+-M++-carboxymethyl cellulose.