Cationic disulfide-functionalized worm gels. Issue 38 (12th September 2017)

• Record Type: Journal Article
• Authors: Ratcliffe, L. P. D.; Bentley, K. J.; Wehr, R.; Warren, N. J.; Saunders, B. R.; Armes, S. P.
• Is Part Of: Polymer chemistry. Volume 8:Issue 38(2017)
• Page Start: 5962
• Page End: 5971
• Publication Date: 2017-09-12
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c7py01306j
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Two types of cationic disulfide diblock copolymer worm gels are prepared by reacting cystamine with epoxy groups located within the steric stabilizer chains. Abstract : The recent development of polymerization-induced self-assembly (PISA) has facilitated the rational synthesis of a range of diblock copolymer worms, which hitherto could only be prepared via traditional post-polymerization processing in dilute solution. Herein we explore a new synthetic route to aqueous dispersions of cationic disulfide-functionalized worm gels. This is achieved via the PISA synthesis of poly[(glycerol monomethacrylate- stat -glycidyl methacrylate)]- block -poly(2-hydroxypropyl methacrylate) (P(GMA- stat -GlyMA)-PHPMA) block copolymer worms via reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization of HPMA. A water-soluble reagent, cystamine, is then reacted with the pendent epoxy groups located within the P(GMA- stat -GlyMA) stabilizer chains to introduce disulfide functionality, while simultaneously conferring cationic character via formation of secondary amine groups. Moreover, systematic variation of the cystamine/epoxy molar ratio enables either chemically cross-linked worm gels or physical (linear) primary amine-functionalized disulfide-based worm gels to be obtained. These new worm gels were characterized using gel permeation chromatography, 1 H NMR spectroscopy, transmission electron microscopy, dynamic light scattering, aqueous electrophoresis and rheology. In principle, such hydrogels may offer enhanced mucoadhesive properties.