THERMAL EFFECTS ON THE OPTICAL-SPECTRA OF A POLYDIACETYLENE - POLY(1,2-BIS[4-(ISOPROPYLCARBAMOYLOXY)-NORMAL-BUTYL]-1-BUTEN-3-YNYLENE)

The reflection spectra of single crystals of the polydiacetylene, IPUDO [R=(CH2)4OCONHCH (CH3)2], were measured between 25° C and 160° C. A nearly reversible thermochromic change is observed together with a variation of hysteresis upon cycling. The latter is attributed to annealing that permits the pendant groups to adopt a conformation which favors the butatriene-type configuration of the polymer at high temperatures. Intensities of the high and low temperature spectra obtained by Kramers-Kronig transforms are in excellent agreement with the spectral intensities of polydiacetylenes which are prototypes for the two configurations. © 1979 American Institute of Physics.