Thermal and crystalline properties of poly(2-oxazoline)s

Poly(2-substituted-2-oxazoline)s (POxs), regarded as synthetic pseudo-polypeptides, are of special interest due to their relative ease of preparation, modification possibilities and biocompatibility. Due to these properties, POxs have been investigated for a wide range of applications, including biomedical. This review gathers together data on the thermal and crystalline properties of POxs that could be helpful in designing new poly(2-oxazoline)s materials with strictly defined parameters. In the first part, a comprehensive overview of the thermal and crystalline properties of POxs in the solid state is provided. Special attention has been paid to the possibility of adjusting these properties by the copolymerization of appropriate monomers. Additionally, possible polymer chain conformations during crystallization in the solid state are discussed. In the second part, the properties of POxs crystallized from the solutions are summarized, with a special emphasis on 2-isopropyl-2-oxazoline-based (co)polymers. Here, we also consider the mechanism of crystallization from solution. At the end, the use of crystalline POxs in some applications is briefly presented.