Thermal transitions in α,ω-diamino terminated poly(oxypropylene)-block-poly(oxyethylene)-block-poly(oxypropylene) aqueous solutions and their epoxy networks

Thermal transitions in α,ω-diamino terminated poly(oxypropylene)-block-poly(oxyethylene)-block-poly(oxypropylene), POP-POE-POP, aqueous solutions were studied in a broad temperature range from −100 °C to 50 °C. The solutions of different polymer weight fractions (from 0 to 1) were investigated in cooling and heating scans of differential scanning calorimetry. Qualitatively different kinds of thermograms are found that include crystallization and melting of the polymer chains and water molecules, glass transition, eutectic composition and the existence of non-crystallizable water. All these features are explained on the basis of the transitions diagram of the system, that is obtained for the first time for this important block copolymer in such a broad temperature range. The information obtained from the phase diagram is used in a better understanding of the thermal transitions of swollen epoxy networks based on POP-POE-POP at different cross-linking and hydrophobic degrees.