Single-ion-conducting polymer electrolytes (SICPEs) based on polystyrene and poly(ethylene oxide) block copolymers (PS-b-PEO) are promising materials due to the combination of high stability and exclusive charge transport via lithium cations. However, the incorporation of covalently attached anions into the flexible polyether block to yield SICPEs is a synthetic challenge. For this purpose, a polystyrene-b-multifunctional poly(ethylene oxide) block copolymer precursor (M n = 15.1 kg•mol −1 , Đ = 1.09) with randomly distributed multiple hydroxyl functional groups (6% mol ) in the polyether block was synthesized by the combination of living carbanionic and anionic ring-opening polymerization (AROP). First, living polystyryl lithium was endfunctionalized with ethylene oxide (EO). Subsequently, AROP copolymerization of EO and ethoxy vinyl glycidyl ether (EVGE) was initiated by the alkoxide-functional polystyrene macroinitiator, followed by deprotection of the vinyl ether groups. A novel postpolymerization Mitsunobu reaction was developed to quantitatively substitute the hydroxyl groups with tert-butyloxycarbonyl (BOC)-protected trifluoromethanesulfonamide (TFSA) functionalities. The SICPE material was obtained in a following deprotection and deprotonation step of the TFSA groups. All reaction steps were monitored via detailed NMR, IR, and sizeexclusion chromatography (SEC) characterization. The ionic conductivity of the obtained SICPE was compared and contrasted against the established dual-ion conductors PS-b-PEO doped with LiTf and LiTFSI. It was demonstrated to have superior ionic conductivity to PS-b-PEO/LiTf. In addition, the Li-ion conductivity is comparable to the single-ion block copolymer electrolyte poly(ethylene oxide)-b-poly(styrenesulfonyl(lithium trifluoromethylsulfonyl)imide) (PEO-b-PSLiTFSI) within the ordered state.

End group functionality is a key parameter of functional polymer chains. The end-capping efficiency of living polystyryl lithium with various epoxides, namely ethylene oxide (EO), ethoxy ethyl glycidyl ether (EEGE) and isopropylidene glyceryl glycidyl ether (IGG), is investigated with solvent gradient interaction chromatography (SGIC). Generally, end-capping efficiencies >95% are observed. Hydroxy functional polystyrene (PS-OH, PS-EEGE-OH, and PS-IGG-OH) with molar masses ranging from 13.8 to 15.0 kg mol −1 are obtained, with dispersities of 1.05-1.06. Deprotection of the acetal (PS-EEGE-OH) and ketal protective group (PS-IGG-OH) is investigated. Nearly quantitative deprotection (>99%) resulting in the corresponding multihydroxy functional PS (PS-(OH) 2 and PS-(OH) 3 ) are observed via SGIC. Esterification of PS-OH with succinic anhydride shows a conversion of 98% to the corresponding ester. A detailed picture of side reactions during the carbanionic polymer synthesis subsequent epoxide termination is obtained, demonstrating 95-99% terminal functionality. Depending on the polarity of the end group, an elution order of PS-OH < PS-(OH) 2 < PS-(OH) 3 < PS-COOH is obtained in SGIC. The study demonstrates both the analytical power of SGIC and the exceptionally high terminal functionalization efficiency of anionic polymerization methods.

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Dedicated to Brigitte Voit on the occasion of her 60th birthdayIn-depth understanding of copolymerization kinetics and the resulting polymer microstructure is crucial for the design of materials with well-defined properties. Further, insights regarding the impact of solvents on copolymerization kinetics allows for precisely tuned materials. In this regard, in situ 1 H NMR spectroscopy enables precise monitoring of the living anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) with the glycidyl ethers allyl glycidyl ether (AGE) and ethoxy vinyl glycidyl ether (EVGE), respectively. Determination of reactivity ratios reveals slightly higher reactivity of both glycidyl ethers compared to EO, emphasizing a pronounced counterion chelation effect by glycidyl ethers in AROP. Implementation of density functional theory (DFT) calculations further illustrates the complexation capability of ether-containing side groups in glycidyl ethers, in analogy to crown ethers ("crown ether effect"). Investigation of the copolymerization in i) THF-d 8 and ii) DMSO-d 6 shows an increasing disparity of reactivity ratios for both glycidyl ethers compared to EO, clearly related to decreasing solvent polarity.

Statistical copolymers of linear glycerol (linG) and ethyl glycidyl ether (EGE) show tunable thermoresponsive behavior. The cloud point of the highly biocompatible copolymers is tailored by polymer composition and concentration.