Preparation method of modified starch ether for improving anti-sliding property of ceramic tile adhesive

A preparation method of modified starch ether for improving the anti-sliding property of a ceramic tile adhesive, comprising chemical modification of subjecting starch to one-step etherification to obtain starch ether, followed by physical modification;

• wherein, the chemical modification of one-step etherification comprises:
• mixing tapioca starch, an alkalizer, an alcohol and an inhibitor to form a mixture, into which an etherifying agent is added;
• and
• subjecting the mixture to etherification, which is initially conducted at a lowered temperature of 10 to 20° C. for 1.5 to 2.5 hours, and then conducted in stages at different raised temperatures, comprising a stage at 40° C. for a period of 2.5 to 3 hours and a further stage at 60° for a period of 4 to 5 hours;
• wherein, the tapioca starch, the alkalizer and the etherifying agent are used in the onestep etherification at a mass ratio of 1:(0.01-1):(0.02-1.2);
• wherein, the etherifying agent is a mixture of propylene oxide and ethylene oxide, or a mixture of chloroacetic acid, propylene oxide, and ethylene oxide;
• and wherein, the tapioca starch and the alcohol are used in the one-step etherification at a mass ratio of 1:(0.1-0.3);
• and wherein,
• the physical modification is conducted by mixing the starch ether with an thickener and a rheological agent for 40 min to 60 min;
• wherein, the thickener is hydroxypropyl methyl cellulose and/or hydroxyethyl methyl cellulose, the rheological agent is one or more of guar gum, carrageenan and xanthan gum, and the starch ether, the thickener and the rheological agent, in percentage by weight, are 20% to 30%, 64% to 76%, and 4% to 6%, respectively.