METHOD FOR PREPARING HIGH-ADAPTABLE ETHER POLYCARBOXYLATE SUPERPLASTICIZER AT LOW TEMPERATURE

The present invention provides for preparing high-adaptable ether polycarboxylate superplasticizer at low temperature, which comprises the steps of mixing unsaturated carboxylic acid, unsaturated sulfonate, unsaturated phosphonic acid, chain transfer agent and water to form solution A; mixing reducing agent C and water to form solution B; putting unsaturated polyoxyethylene ether, buffer and water into reactor at a reacting temperature ranging from 10 to 40 , then adding oxidizing agent and stirring to make it dissolve; dropping solution A and solution B into the reactor separately in 2~4 hours; adding 0~0.5 pbw reducing agent D and continuing racting for 1~2 hours after dropping is finished; and neutralizing the system by adding 10~20 pbw 30 wt pcnt NaOH solution. The present method is simple while the polycarboxylate superplasticizer performs high dispersion. The low-temperature polymerization of polycarboxylic acid is achieved by introducing low-temperature and high efficiency reducing agent, which also improve the conversion rate.