Effect of Dilution on Structure and Properties of Polyurethane Networks. Pregel and Postgel Cyclization and Phase Separation
2010
Abstract
Bi-, tri-, and tetrafunctional star-shaped polyol precursors were cross-linked with a star-shaped triisocyanate and the effect of the presence of diluent during network formation on the gel-point conversion and on the equilibrium elastic modulus was studied. The dependence of on reciprocal concentration of functional groups was fairly linear and extrapolated for well to the value calculated for the ring-free system using the branching theory.