Preparing hyperbranched polycarboxylate superplasticizers possessing excellent viscosity-reducing performance through in situ redox initialized polymerization method

摘要

Significant improvements to modern concrete have emerged in recent years, primarily due to application of various polycarboxylate dispersant with designed structure. However, self-compacting or high strength concrete characterized by a low water-to-cement ratio (w/c) pose challenges for their viscosity and pumpability. Here we propose a strategy so called in situ redox polymerization method to synthesis hyperbranched polycarboxylate superplasticizers. By adopting a unique monomer Dimethylaminoethyl Methacrylate, acting as monomer as well as initiator, hyper-branched structure are obtained through this one-pot synthesis procedure. In contrast to their conventional counterparts, that is, comb-like polycarboxylate, hyperbranched structure is shown to cut down the viscosity of pore solution and alleviate the shear thickening behavior of cement paste, leading to a 30% reduction in viscosity of paste. Moreover, owing to the ease of industrial manufacture, our approach, in situ redox polymerization method, show broad prospects and great potential for development.