Polyurethane networks decreasing cross-linking

In general, the interdomain space of the segmented polyurethanes decreases with an increase of HSC. But at HSC = 45%, the interdomain space increases slightly. This may be attributed to the discontinuity-continuity transition of the hard phase. The decrease of the interdomain space with the increase of HSC suggests the increasing concentration of the hard domains, i.e., the physical cross-linking density of the polyurethane cross-linked networks. 

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