Polyurethane melt viscosity, increase

The last four entries of Table 43.1 represent a preformed polyurethane and polyrotaxanes derived by threading crown ethers onto it in the melt. Since the backbone molecular weight is constant, this series allows us to discern the effect of rotaxanation on the intrinsic viscosity. As can be seen in Fig. 43.2, in fact, the intrinsic viscosity increases linearly... 

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