Since synthesis of poly(2-propyl-4-methyl-2-oxazoline) (pPrMeOx) and its characteristics were not reported before, the respective homopolymers were synthesized and characterized first. Knowledge of the homopolymerization and homopolymer properties are also important to support the synthesis of corresponding polymer amphiphiles and their characterization. Also, this allows a direct comparison with its isomer pEtEtOx. Accordingly, the homopolymers p R EtEtOx, p S EtEtOx, p RS EtEtOx, p R PrMeOx, p S PrMeOx and p RS PrMeOx were prepared by LCROP. Using a [M]0/[I]0 = 20, the complete polymerization of monomers R EtEtOx, S EtEtOx and RS EtEtOx was achieved only after about 45 h at 130 °C. In comparison, the monomer consumption for R PrMeOx, S PrMeOx and RS PrMeOx was complete after only approximately 24 h at 130 °C, which can be attributed to decreased steric hinderance due to the smaller Me substituent at the 4-position affecting the nucleophilic attack of monomer at the 5-position. We tested the solubility of homopolymers in different solvents used in following experiment. All these homopolymers are well soluble in HFIP (≥ 5 g/L) and excellently soluble in chloroform, methanol and ethanol (all ≥ 200 g/L), but poorly soluble in water (< 0.5 g/L in water). The poor water solubility is roughly in line with the wellknown side chain size dependence of POx solubility. Interestingly, when the saturated aqueous solutions of the homopolymers equilibrated at 4 °C were brought to room temperature, the previously clear solutions turned turbid. Surprisingly, the concentration of saturated aqueous solutions (4 °C) was 8-10 g/L (Table ), much higher than that at room temperature. This observation shows that these homopolymers exhibit a thermoresponsive behaviour (LCST-type) in water. The LCST behaviour is well known for POx and POzi with C3 side chains , but, to the best of our knowledge, has not been described for higher substitution in published research.