Cold crystallization of water in hydrated poly(2-methoxyethyl acrylate) (PMEA)

The structure of water associated with poly(2-methoxyethyl acrylate) (PMEA), which is known to exhibit excellent blood compatibility, has been investigated using differential scanning calorimetry (DSC). The total equilibrium water content (EWC) of PMEA was 9.0 wt%. Water in the PMEA could be classified into three types: non-freezing, freezing-bound and free water. Cold crystallization of water was clearly observed at about −42 °C on heating when the water content was more than 3.0 wt%. Cold crystallization is attributed to the phase transition from the amorphous ice to the crystal ice in PMEA. The relative proportions of freezing-bound water at the EWC is 48 % of all the water in hydrated PMEA.