低活性高和易性酯类大单体的制备及其抗收缩性能研究OACSTPCD

Solving the sensitivity of concrete to admixture dosage and concrete shrinkage has always been a technical challenge eagerly awaited in the construction industry.A new type of ester polycarboxylate superplasticizer monomer(ACPEG)was synthesizeduses by 3-methyl-3-butenoxyacetic acid(MBA)as the priming agent.The relative molecular mass(Mw)of ACPEG was determined to be 2 389 by an multi-angle laser dispersion spectrumeig scattering instrument,indicating the formation of a polyether monomer structure.The results showed that ACPEG has a unique advantage of low polymerization activity,allowing for the one-step synthesis of superplasticizers at 40℃without risk of explosion.The superplasticizer synthesized from ACPEG exhibited a water-reducing rate of 37.4%,segregation rate of 10.8%,bleeding rate of 6.2%at 1 hour,and surface tension of 35.67 mN/m.Although slightly inferior to superplasticizers synthesized from ester-type monomers(MAPEG)in terms of workability,ACPEG outperformed superplasticizers synthesized from methallyl polyethylene glycol ethers(IPEG)and isoprene polyethylene glycol ethers(TPEG)in concrete slump,bleeding distance,segregation rate,workability,and shrinkage reduction effects.