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Chain conformational distribution of a biodegradable polyester elastomer, poly(p-hydroxy­octanoate) (PHO), has been analyzed using vibrational spectroscopy in conjunction with normal vibrational analysis. For the as-prepared, mainly amorphous materials, side-chain conformation distribution is extremely broad and is consistent with the expected three-state rotational isomeric model. On the basis of our vibrational analysis, we have established that side-chain conformational distribution transforms to one containing mainly the extended form after thermal annealing. In contrast, the conformational distribution of the side chains remains unchanged as a function of strain. Additionally, the carbonyl stretching vibrations were found to be sensitive to changes in the crystalline …

Segmented liquid crystalline polyurethanes (LCPUE) have been studied by infrared

spectroscopy. The nematic liquid crystalline hard domains act as physical cross-links and can be oriented

by the application of mechanical strain. The orientation function achievable in the hard segments results

from the combination of mechanical strain and stress-softening. Furthermore, elastic deformation induces

the rearrangement of some hard segments in the mesophase into a more ordered packing. Hightemperature

infrared spectra have been correlated with thermal transitions of the LCPUE, and a liquidliquid

microphase-separated morphology above the isotropization of the mesophase appears to exist.