Phase diagrams of blends of azide-containing polyoxetanes

The mutual solubility of polymers based on the azide-containing oxetane monomers 3,3-bis(azidomethyl)oxetane and 3-azidomethyl-3-methyloxetane is studied. The temperatures of melting, crystallization, glass transition; the upper critical solution temperature; and the compositions of coexisting phases for blends of polymers with different molecular masses are determined via differential scanning calorimetry and multiple-beam microinterferometry. On the basis of these data, the phase diagrams of blends are constructed. The melting regions and the metastable and heterogeneous states are determined. The studied systems are shown to have a complex amorphous-crystalline equilibrium and to differ in the location of boundary curves on the phase diagram, depending on the molecular mass of the components. Amorphous separation below the liquidus line in the metastable region with respect to the crystalline equilibrium is experimentally detected. The motion of the figurative point in different regions of the diagram is thoroughly considered. The specifics of structural and morphological organization of systems are examined via electron microscopy.