Rheo‐Optical Fourier‐Transform Infrared Spectroscopy of Polymers 14. Segmental Orientation and Strain‐Induced Crystallization of a Poly(Ether Urethaneurea) Elastomer

The versatility and potential of rheo‐optical Fourier‐Transform infrared (FTIR) spectroscopy is demonstrated with reference to the characterization of segmental orientation in a poly(ether urethaneurea) elastomer. The rheo‐optical data show that the soft and hard segments of the polymer deform by different orientation mechanisms. Thus, the soft segments exhibit an almost perfect reversibility of orientation and desorientation in loading and unloading cycles, whereas the deformation of the hard segments is dominated by a significant reorganization of their morphology. Furthermore, rheo‐optical FTIR spectroscopy provided an extremely sensitive tool for detecting the onset, progress and decay of strain‐induced crystallization of the soft segments during the mechanical treatment of the elastomer.