Synthesis, characterization and solution properties of a double-hydrophilic multiblock copolymer with sulfonic groups

The double-hydrophilic multiblock copolymers poly(ethylene glycol)-b-poly((2-acrylamido-2-methyl propanesulfonic sodium) (PEG-b-PAMPSNa) with different PEG and PAMPSNa ratio have been synthesized. The copolymers were characterized by FTIR, ¹H-NMR, elemental analysis, thermogravimetric analysis (TGA) and Gel permeation chromatography coupled with multi-angle light scattering laser light scattering (GPC-MALLS). According to the results, it was seen that the compositions had obvious influences to the characteristics of the copolymers. With more PEG content in the copolymers, the molecular weights and thermal stability increased, and the copolymers chain structures were more flexible. The solution properties of the copolymers were studied by dynamic light scattering (DLS), which also have great relationship with the copolymers compositions. And PEG-b-PAMPSNa was used as a crystal growth modifier to control the crystallization of BaSO₄ in its aqueous solution. The morphologies and sizes of BaSO₄ crystals can be well controlled by the copolymer. With the increasing concentration, the copolymer assembled in water and interacted with inorganic particles on the crystal faces, which is concerned with the controlling of crystal growth in solution.