摘要 |
Substances useful as water reducing and superplasticizer additives for cement compositions are formed by reaction of carboxylic acid polymers with a polyether, preferably a mixture of monofunctional and difunctional polyethers, derived from C2-C4 epoxides wherein partial cleavage of the polyethers and esterification of the polyethers and the cleavage products thereof by the other reactant are achieved. In one embodiment, a sulfonic acid is used to catalyze the reaction of poly(acrylic acid), a monofunctional ethylene oxide-propylene oxide copolymer, and a difunctional poly(propylene glycol), at a temperature in excess of 140 DEG C. |