| abstract |
BIOMEDICAL SEPARATION DEVICES AND THEIR PROCESS FOR OBTAINING. THESE DEVICES, FOR EXAMPLE HOLLOW FIBER, USE POLYURETHANE COMPOSITIONS. THE SEPARATOR DEVICE INCLUDES AT LEAST ONE MEMBRANE OF A TYPE CORRESPONDING TO THE ENVISAGED APPLICATION, WHICH IS FIXED OR WRAPPED IN AN ENCLOSURE WITH A COMPOSITION OF HARDENED POLYURETHANE. THE IMPROVEMENT OF THE INVENTION CONSISTS OF USING A POLYURETHANE INCLUDING THE REACTION PRODUCT OF A PRE-POLYMER WITH NCO TERMINATION AND OF A POLYESTER DERIVED FROM A LACTON WITH HYDROXY TERMINATION. LACTONE POLYESTER IS FORMED BY REACTION OF A LACTONE SUCH AS CAPROLACTONE WITH A POLYOL SUCH AS 1,6HEXANE-DIOL. THE LACTONE POLYESTER PROVIDES THE COMPOSITION WITH AN ADVANTAGEOUS SET OF PROPERTIES, IN PARTICULAR A LOW VISCOSITY OF THE MIXTURE, A HIGH REACTIVITY (SHORT TIME OF GELIFICATION AND RELEASE) AND SUITABLE HARDNESSES. |