Synthesis and Selective Loading of Polyhydroxyethyl Methacrylate-l-Polysulfone Amphiphilic Polymer Conetworks

Abstract

Polyhydroxyethyl methacrylate-linked by-polysulfone amphiphilic polymer conetworks of two types of segments with T g above room temperature are presented. The conetworks are prepared by free radical copolymerization of methacryloyl-terminated PSU macromers with 2-ethyl methacrylate, followed by removal of the TMS protecting groups by acidic hydrolysis. Phase separation in the nanometer range due to the immiscibility of the two covalently linked segments is observed using transmission electron and scanning force microscopy. The swelling of the conetworks in water and methanol as polar solvents and chloroform as nonpolar solvent are studied gravimetrically and then in a more detailed fashion by solid-state NMR spectroscopy. Selective swelling and also targeted loading of a small organic model compound specifically to one of the two phases are demonstrated.

Wide Range of Functionalized Poly(N-alkyl acrylamide)-Based Amphiphilic Polymer Conetworks via Active Ester Precursors

“…The challenge for the fabrication of APCNs lies within the necessity to combine two immiscible polymers into a macroscopically homogeneous material. Synthetic strategies are typically based on either cross-linking of preformed polymer segments, ,− sequential living polymerization and cross-linking, − or the polymerization of hydrophilic monomers with hydrophobic macromonomer cross-linkers, ,,,− with the last one representing the historically most employed approach. All strategies result in conetwork structures where covalent bonds inhibit macrophase separation.…”

“…All strategies result in conetwork structures where covalent bonds inhibit macrophase separation. However, the use of amphiphilic solvents is usually required to provide miscibility of the components during the conetwork preparation, if it is possible at all, with one exemption: The use of hydrophilic monomers bearing highly hydrophobic masking groups allows for the combination with even extremely hydrophobic macromonomers, while enabling polymerizations in bulk or with very little solvent addition. ,,− , For example, 2-hydroxyethyl acrylate (HEA) was made miscible with a dimethacrylate-terminated poly­(dimethylsiloxane) (MA-PDMS-MA) by modification of its hydroxy group with the hydrophobic trimethylsilyl (TMS) group. The masking group was cleaved off after the polymerization, leaving behind an APCN with a hydrophilic poly­(HEA) and a hydrophobic PDMS phase .…”

Nanophasic morphologies as a function of the composition and molecular weight of the macromolecular cross-linker in poly(N-vinylimidazole)-l-poly(tetrahydrofuran) amphiphilic conetworks: bicontinuous domain structure in broad composition ranges

“…These novel polymeric systems belong to a rapidly emerging class of materials and have sparked enormous interest in the last few decades in both pure and applied sciences. 7,8,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] APCNs possess several unique characteristics, such as the amphiphilic swelling properties and the improved mechanical characteristics compared to homopolymer hydrogels. Moreover, a special property of these materials is their phase behaviour.…”

Structural Study of Four-Armed Amphiphilic Star-Block Copolymers: Pristine and End-Linked Tetronic T1307

“…There has recently been significant interest from both fundamental and applied points of view to make ideal network systems. − Sakai, Shibayama, and co-workers presented recently a tetra-PEG gel system based on molecular four-armed star-architectures. − These basic PEG-star networks are somewhat related to the cross-linked system presented in this paper, but obviously without the property of self-assembly. The polymers were made up of a 1:1 blend of tetra-amine-terminated (TAPEG) and tetra-NHS-glutamine-terminated (TNPEG) four-arm PEG macromers.…”