Preparation And Performance Of Polyether-Based Superplasticizer

The polycarboxylic acid based superplasticizer (PC) has gotten wide spread attention both at home and abroad because of its various performance advantages. The polyether-based superplasticizer is usually classfied as the second generation of PC, which has become the focus of recent research for its simple one-step synthesis process and convenient raw material availbility.This research has studied the synthesis process of the polyether-based superplasticizer using allyl polyethylene glycol (APEG) as the main raw material. Through the study on different reaction systems and the matching properties of various monomers, a four-component-system was selected and the appropriate radical polymerization method was determined. The monomer proportion ratios of this system was optimized by employing orthogonal design. The feeding method of adding the active monomer mix and initiator solution separately in drop wisely at the same time is preferable, and the effect of temperature, reaction duration, concentration and other factors on the performance of the final product were investigated also.By using the techniques of infrared spectrum and laser multi-angle scattering method, the functional groups, the molecular weight and molecular weight distribution of the synthesized polymer were determined and analyzed. In addition, the TOC method was tentatively used to measure the adsorptive behaviours of polyether-based superplasticizer in cement system. Test results of cement hydration heat evolution and cement concrete applicaiton properties indicate that the polyether-based superplasticizer has strong ability of dispersion and dispersion retention, especially in the case of low water-cement ratio. The compatibility of the synthesized polymer with different kinds of cement is satisfactory.The related theories and mode of polymerization reaction were discussed and the gradient theory of monomer activity was put forwarded according to the comprehensive test results. Furthermore, the proportion of functional groups in this superplasticizer was caculated, the relationship between configuration and performance of the polymer was discussed.