engleski

Phase morphology of functionalized polyester polyurethanes. Effect of functional groups concentration

Segmented polyester polyurethanes (PU) based on polycaprolactone as a soft segment and a hard segment containing isophoronediisocyanate and chain extenders 2, 2¢ ; ; ; -bis-(hydroxymethyl) propionic acid and 1, 4-butanediol with different molar ratios were prepared. The changes of crystallinity and morphology due to the incorporation of carboxylic functional groups in the hard segment were monitored by wide-angle X-ray diffraction, WAXD, optical microscopy and differential scanning calorimetry, DSC. The concentration of functional groups varied from 0 to 0.45 mmol g-1. The phase separation, degree of crystallinity and the size of spherulites depend on the interactions imposed by functional groups. A critical level of the concentration of functional groups (0.25 mmol g-1) at which the crystallizability reaches maximum is observed.

polyester polyurethanes ; functionalization ; morphology ; crystallinity ; phase separation

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