Study on synthesis and gelation reaction of cationic copolymer containing sulfhydryl groups.

With HEMA and DMC as comonomers, the water-soluble copolymer mercapto-poly (methacrylic acid-β-hydroxyethyl (HS-P (HEMA-co-DMC)) containing hydroxyl, mercapto and ammonium cations in the side chain was prepared by free radical polymerization and sulfhydryl conversion reaction. The rheological properties and morphology of the two types of composite hydrogels, which were formed by HS-P (HEMA-co-DMC) reacting respectively with polyethylene glycol diacrylate (PEGDA) and surface-loaded laponite (Laponite RD) by the physical / chemical cross-linking reaction, were measured by rheometry and SEM. The results showed that the gel storage modulus and loss factor of HS-P ( HEMA-co-DMC )/LaponiteRD composite hydrogel were respectively 3468 Pa and 0. 34 with a solid content of 22%, showing obvious viscoelastic behavior of the crosslinked points. At the same solid content, HS-P ((HEMA-co-DMC)/PEGDA composite hydrogel had a storage modulus of 1484 Pa and a loss factor of 0.013, showing the viscoelastic behavior of a typical covalently crosslinked gel. HS-P ((HEMA-co-DMC)/Laponite RD composite hydrogel had a denser pore structure than HS-P (HEMA-co-DMC)/PEGDA composite hydrogel. [ABSTRACT FROM AUTHOR]