TY - THES ID - 136258075 TI - Thermo-responsive Copolymers: Synthesis, Characterization and LCST demixing behavior in water. AU - Merchiers, Jorgo AU - Nies, Eric AU - Smet, Mario AU - KU Leuven. Faculteit Wetenschappen. Opleiding Master in de chemie (Leuven) PY - 2017 PB - Leuven KU Leuven. Faculteit Wetenschappen DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:136258075 AB - In this thesis, fundamental research was performed to the phase behavior of certain water-soluble polymers, based on Poly Vinyl Methyl Ether (PVME), which are characterized by a very peculiar type III bimodal LCST. This PVME was synthesized via a special strategy. Not only PVME but also copolymers of PVME with Vinyl Alcohol (VA) and Vinyl Acetate (VAc), in two different chemical compositions were formed in a similar way to investigate the influence of, respectively, hydrophilic/hydrophobic interactions with the solvent. The synthesis of the (co)polymers was done in several steps, where the first step was the synthesis of Poly Vinyl Acetate (PVAc) via the, rather uncommon, Cobalt-Mediated Radical Polymerization (CMRP) of VAc. Well-defined PVAc chains were able to be formed via this polymerization reaction, with different molar masses and a low polydispersity (Đ). In a next step, a Side Chain Modification Reaction, a methylation reaction to be more specific, was performed on this PVAc to obtain copolymers of Vinyl Methyl Ether (VME) with VA, in a composition of 93% VME and 7% VA, more or less. Higher methylation values were obtained by performing the same reaction again, in the presence of a stronger base, by which a copolymer of 96% VME and 4% VA, and a 100% PVME polymer were formed. In a final step, the alcohol functions in the copolymer were acetylated via a so-called DMAP catalyzed acetylation reaction, in which copolymers of the same compositions and characteristics were formed, and only the VA group was substituted by a VAc group. Proton Nuclear Magnetic Resonance (1H-NMR) and Size Exclusion Chromatograhy (SEC) techniques were used to characterize these polymers in their synthetic procedures. Eventually, the LCST phase behavior of these (co)polymers was examined, together with the influence of the other functional groups than VME. Differential Scanning Calorimetry (DSC) and Optical Microscopy (OM) were used for examination of the phase behavior of the products, in a 5% w/w aqueous solution. During the synthetic steps, salts were formed, which were removed as much as possible and the final amounts of salts that could not be removed were measured via Inductive Coupled Plasma (ICP-OES). ER -