| 摘要 |
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. |
