AIR CONTROLLING SUPERPLASTICIZERS

Polymeric additives for hydraulic cement compositions which impart to the we t cement composition greater plasticity, lower slumploss over time, and water reduction capability without the problems of air entrainment associated with prior polymeric additives of this type. The superplasticizers have a carbon backbone formed by polymerization of ethylenically-unsaturated carboxylic acids, the backbone comprising carboxylic acid grafting sites to which are covalently attached a) air detraining functional side chains, which are firs t polyoxyalkylene groups of the general formula: R4-(OA2)x-Q-, wherein Q = O o r NH; A2 = C1-C10alkylene; x = 1 to 200; and R4 = C1-C10alkyl, and b) second polyoxyalkylene groups of the general formula R5-O-(A3O)y-(A3)p-N=, wherein A3 = C1-C10alkylene; y = 1 to 200; p = 1 to 50; and R5 = C1-C10alkyl. Polymeric additives for hydraulic cement compositions which impart to the wet cement composition greater plasticity, lower slumploss over time, and water reduction capability without the problems of air entrainment associated with prior polymeric additives of this type. The superplasticizers have a carbon backbone formed by polymerization of ethylenically-unsaturated carboxylic acids, the backbone comprising carboxylic acid grafting sites to which are covalently attached a) air detraining functional side chains, which are first polyoxyalkylene groups of the general formula: R4-(OA2)x-Q-, wherein Q = O or NH; A2 = C1-C10alkylene; x = 1 to 200; and R4 = C1-C10alkyl, and b) second polyoxyalkylene groups of the general formula R5-O-(A3O)y-(A3)p-N=, wherein A3 = C1-C10alkylene; y = 1 to 200; p = 1 to 50; and R5 = C1-C10alkyl.