Study on the monomer reactivity ratio and performance of EPEG-AA (ethylene-glycol monovinyl polyethylene glycol–acrylic acid) copolymerization system

EPEG (ethylene-glycol monovinyl polyethylene glycol)-AA (acrylic acid) copolymerization is a typical representative of free radical copolymerization for the preparation of PCs that has been discussed and used increasingly in recent years. The calculation of the reactivity ratio can be used for the analysis of the monomers reactivity, which is of great significance to the study of copolymerization process. In this paper, combined with GPC test results, the monomer reactivity ratios in EPEG-AA copolymerization were calculated with the linear (Fineman–Ross, YBR, Kelen–Tüdös) methods and the nonlinear least square method, and the uncertainty of the methods were calculated. In addition, it has been found that compared with the widely used IPEG (isobutylene polyethylene glycol)-AA copolymerization, the monomer activity of EPEG is higher and closer with AA, so the copolymerization efficiency should be higher. This problem has been verified by experimental results, and the unity of theory and experiment has been realized. At the same time, the experimental results show that the PCs prepared by EPEG macromonomers have better dispersion of cement paste. To sum up, EPEG macromonomer will be more widely used in the future.