Anionic amphiphilic end‐linked conetworks by the combination of quasiliving carbocationic and group transfer polymerizations

Abstract

A series of amphiphilic end-linked conetworks was synthesized by the combination of two ''quasiliving'' polymerization techniques, quasiliving carbocationic (QLCCP) and group transfer polymerizations (GTP). The hydrophobic monomer was polyisobutylene methacrylate synthesized by the QLCCP of isobutylene and subsequent terminal modification reactions. The hydrophilic monomer was methacrylic acid (MAA) introduced via the polymerization of 2-tetrahydropyranyl methacrylate followed by acid hydrolysis after (co)network formation. The conetwork syntheses were performed by sequential monomer/crosslinker additions under GTP conditions. All the precursors and the extractables from the conetworks were characterized by gel permeation chromatography and 1 H NMR. The resulting polymer conetworks were investigated in terms of their degree of swelling (DS) in aqueous media and in tetrahydrofuran (THF) over the whole range of ionization of the MAA units and in nhexane for uncharged conetworks. The DSs in water increased with the degree of ionization (DI) of the MAA units and the hydrophilic content in the conetwork, whereas the DSs in THF increased with the reduction of the DI of the MAA units. The effective pK of the MAA units in the conetworks increased from 8.4 to 10.5 with decreasing MAA content. These findings can facilitate the design of similar unique conetworks with adjustable swelling behavior and composition-dependent pK values.

Thermoresponsive terpolymers based on methacrylate monomers: Effect of architecture and composition

“…The M n s of the polymers and their precursors were higher than the theoretical M w s due to partial deactivation of the initiator. This is in agreement with other studies where the polymers were synthesized by GTP and a high M w monomer, like PEGMA, was used which could not be distilled 38–41…”

Tailoring pH-responsive acrylic acid microgels with hydrophobic crosslinks for drug release

“…The protective group of tetrahydropyranyl was chosen because is a good leaving group and it can be easily be hydrolysed even in macrogels. [28][29][30][31] The hydrolysis of the THPA groups produced anionic gels and we have chosen anionic gels because they have shown promised in drug delivery 32 and protein delivery 33 . Specifically in this study microgels of differing crosslinking ratios were produced, collected and polymerised off the chip and then hydrolysed to produce AA based microgels.…”

Biocompatible amphiphilic conetwork based on crosslinked star copolymers: A potential drug carrier

“…Amphiphilic conetwork (APCN), a novel polymeric material consisting of hydrophilic and hydrophobic polymer segments through covalently interconnection, has become one of the forefronts in biomaterial research . The extraordinary composition of the networks exhibit unique properties, that is, swelling dependence on solvent, phase separation at nanoscale, mechanical stability, and excellent biocompatibility, which renders them suitable for versatile applications in controlled drug delivery, extended‐wear contact lenses, and biochemical sensors …”