Synthesis, characterization and modification of hyperbranched polyether polyol copolymers

Abstract

This thesis aims to develop and improve the synthesis, characterization and modification of hyperbranched polyether polyol copolymers based on glycidol as a branching agent and other epoxide monomers, particularly ethylene oxide (EO), propylene oxide (PO) and 1,2-butylene oxide (BO).

Chapter 1 summarizes the state of the art concerning the synthesis of star-shaped and hyperbranched polymers from ethylene oxide, propylene oxide and 1,2-butylene oxide. Furthermore, it provides an overview of the synthesis, properties, and applications of poly(propylene oxide), poly(butylene oxide) and higher poly(alkylene oxide)s in general.

Novel synthetic strategies and detailed characterization methods for hyperbranched poly(alkylene oxide)s are presented in Chapter 2. Hyperbranched poly(ethylene oxide) (hbPEO) and thermoresponsive hyperbranched poly(butylene oxide) (hbPBO) copolymers are prepared both by batch procedures and by applying the slow monomer addition (SMA) technique. In contrast to the batch procedures, the SMA technique enables precise control over the molar masses of the resulting materials. Analytical ultracentrifugation (AUC), intrinsic viscosity, translational diffusion measurements and SEC are combined to determine the molar masses absolutely. The different copolymerization kinetics of the multibranching ring-opening anionic copolymerizations of glycidol with EO, PO and BO are revealed by online 1H NMR kinetic experiments.

The application of hyperbranched poly(alkylene oxide)s as multifunctional initiators for the synthesis of various types of multiarm star copolymers is presented in Chapter 3. Various polyether-polycarbonate multiarm star copolymers are prepared by copolymerization of CO2 with PO and BO from different hyperbranched poly(alkylene oxide) cores. Ultra-high molar mass polyether-polystyrene multiarm star copolymers are synthesized by atom transfer radical polymerization (ATRP), starting from a hbPEO core.

Chapter 4 focuses on the multibranching copolymerization of glycidol with a thioether-functional comonomer, 2 (methylthio)ethyl glycidyl ether (MTEGE). The resulting materials are oxidation-responsive and provide various options for orthogonal post-polymerization modification.