CEMENT ADMIXTURES WITH HIGH RANGE WATER REDUCING EFFECT AND PREPARATION METHOD THEREOF

摘要

PURPOSE: Provided are high range water reducing admixtures comprising at least one of carbonic acid-based copolymers containing surfactant as a monomer and copolymer salts for improving dispersity of cement particles. Accordingly, the admixtures increase the fluidity of cement composition and offer good workability. CONSTITUTION: The admixtures, carbonic acid-based copolymers, contain the components of: (i) 50-90wt.% of alkoxy polyalkylene glycol mono(meth)acrylic acid ester monomer, such as methoxy polyethylene glycol mono(meth)acrylate, expressed by formula 1, wherein R1 is H or CH3, R2O is a mixture of one or more of C2-C4 oxyalkylene, R3 is C1-C4 alkyl and m is the average moles of oxyalkylene and is an integer of 1-50; (ii) 5-45wt.% of (meth)acrylic acid monomer or salt thereof such as metal(M+, M2+) salt of acrylic acid and meta acrylic acid; (iii) 0.5-40wt.% of reactive surfactant, such as sulfoxy polyethylene glycol aryl ether, expressed by formula 3, wherein R5 is H or CH3, R6 is C1-C3 alkylene, phenylene, or alkylphenylene, R7 is a mixture of one or more of C1-C4 oxyalkylene, r is the average moles of oxyalkylene and is an integer of 10-50 by, n is 0 or1, and M2 is H, M+, NH3 or NH2. The admixtures, salts of prepared copolymers, are obtained by neutralizing copolymers with alkali such as hydroxide and chloride of M+ or M2+, ammonia or amine at 0-120deg.C. The weight mean molecular weight of the above copolymers and copolymer salts is 10000-30000. The cement composition contains 0.01-10pts.wt. of cement admixtures, based on 100pts.wt. of cement.