Hyperbranched Polyimides Combined with Linear Polyimides
aDepartment of Polymers and bDepartment of Physical Chemistry, Institute of Chemical Technology, Prague, Technická 5, 166 28 Praha 6, Czech Republic
This work deals with a study of the preparation and characterization of polymeric materials based on the combination of linear and hyperbranched polyimides. The bifunctional 4,4’-oxydiphthalic anhydride and trifunctional 2,4,6-triaminopyrimidine were used for the preparation of hyperbranched polyimide and 4,4’-oxydiphtalic anhydride and 4,4’-oxydianiline for the preparation of linear polyimide. The combined materials were prepared in the form of self-standing films. The weight content of hyperbranched moieties was 25, 50 and 75 wt.%. The tensile strength and modulus of elasticity and also the coefficients of permeability of gases were increasing and the thermooxidative stability decreasing with an increase in the content of hyperbranched polyimide.
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