连续RAFT光聚合法合成聚羧酸减水剂

Preparation of Polycarboxylate-Based Superplasticizer by Continuous Photo-Mediated RAFT Polymerization

以甲基丙烯酸聚乙二醇单甲醚酯和丙烯酸为主要原料,通过光调控水相可逆加成-断裂链转移(RAFT)聚合,在连续管式反应器中成功合成了聚羧酸减水剂,并采用核磁共振仪(NMR)、傅里叶红外光谱仪(FTIR)、凝胶渗透色谱仪(GPC)和动态光散射仪(DLS)等表征了减水剂的结构.结果表明:RAFT聚合聚羧酸减水剂的相对分子质量分布更集中,分散性和分散保持性更好;连续RAFT聚合工艺可以实现可控聚合物的连续化生产,连续管式反应器中有限的氧含量使得RAFT聚合可以在不预先除氧的情况下成功进行,为聚羧酸减水剂的可控合成提供了新的思路.

A kind of polycarboxylate⁃based superplasticizer(PCE)was successfully synthesized by photo⁃mediated reversible addition⁃fragmentation chain transfer(RAFT)polymerization with poly(ethylene glycol)methyl ether methacrylate(PEGMA)and acrylic acid(AA)as the main material.The molecular structure of the products was characterized by nuclear magnetic resonance(NMR),gel permeation chromatography(GPC),infra⁃red spectrum(IR)and dynamic light scattering(DLS).The results show that the product has narrow distribution of the relative molecular mass,the advantages of strong disperse ability and excellent slump retention.Moreover,continuous RAFT process can realize continuous production of controlled polymers.The limited oxygen content in the continuous tubular reactor allows RAFT polymerization to be successfully carried out without prior deoxygenation process,which can provide a new idea for controlled synthesis of polycarboxylate⁃based superplasticizer.