Water-Soluble Poly(vinylferrocene)-b-Poly(ethylene oxide) Diblock and Miktoarm Star Polymers

Abstract

We describe the synthesis of water-soluble diblock and miktoarm star polymers consisting of poly(vinylferrocene) (PVFc) and poly(ethylene oxide) (PEO) blocks. First, end-functionalized poly(vinylferrocene) was generated by end-capping the living carbanionic PVFc chains with benzyl glycidyl ether (BGE) or ethoxy ethyl glycidyl ether (EEGE). Acidic hydrolysis of the EEGE-terminated PVFc partially oxidized the PVFc backbone. However, the dihydroxyl end-functional PVFc was obtained in quantitative yields by hydrogenolysis of the BGE-terminated PVFc. A series of block copolymers and AB2 miktoarm star copolymers was obtained in a second polymerization step, utilizing the respective end-functionalized PVFc as a macroinitiator for the ring-opening polymerization (ROP) of ethylene oxide. All polymers were analyzed in detail, using NMR spectroscopy and size-exclusion chromatography (SEC). Online SEC-viscosimetry as well as MALLS was carried out, confirming the formation of miktoarm structures. Quantitative functionalization and subsequent removal of the acetal and benzyl protective groups, respectively were confirmed by MALDI–ToF mass spectrometry. Molecular weights of the end-functionalized PVFcs range between 1000 and 3600 g mol–1, and block copolymers with 10 000 to 50 000 g mol–1 overall molar masses were synthesized. In addition, the water-soluble block copolymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). For characterization of the morphology in aqueous solution, transmission electron microscopy (TEM) was performed, showing micelles and multicompartment micellar structures.

Stimuli‐Responsive Y‐Shaped Polymer Brushes Based on Junction‐Point‐Reactive Block Copolymers

“…The novel concept relies on recent advances in the fi eld of end [ 41 ] and in-chain [ 42 ] functionalization with epoxide derivatives in our group. [43][44][45] The synthetic strategy developed for the preparation of junction-point-reactive amphiphilic polymers and their attachment to silicon surfaces is shown in Scheme 1 . In the fi rst step, "living" PS [ 46 ] was end-capped with allyl glycidyl ether (AGE) (for experimental details see Supporting Information) to obtain precisely one hydroxyl group and one allyl functionality at the chain terminus (PS-(AGE), 1 ).…”

Sandwich Complex‐Containing Macromolecules: Property Tunability Through Versatile Synthesis

“…In addition to the radical route, anionic homo and copolymerizations have been successfully used to append sandwich complexes to macromolecules . Recently, a copolymerization approach, where the sandwich complex‐containing polymer functions as the initiator in a subsequent polymerization reaction, was successfully used in the synthesis of diblock and miktoarm star copolymers (Scheme ) . The polymerizations involved the prior synthesis of poly(vinylferrocene) (PVFc) by living anionic polymerization and subsequent end capping with benzyl glycidyl ether (BGE) or ethoxy ethyl glycidyl ether (EEGE).…”

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…Metallocene-containing polymers are often related to prominent ferrocene and cobaltocene [136][137][138][139]. Work in this area has been reviewed recently [140][141][142].…”