Cold stretching of PPV with water as a plasticizer

PPV precursors were prepared via the precursor route. The free-standing fil ms were stretched at room temperature under an atmosphere of water vapor. S tretch ratios of up to nine could be attained easily. This procedure is les s dependent on factors such as film thickness and freshness than hot stretc hing. Molecular alignment is at least as good as in hot-stretched films, as proved by FTIR dichroism measurements, Detailed IR results are presented. In addition to providing an experimentally easier way to obtain oriented PP V films, this procedure also allows to produce oriented, noneliminated PPV precursor films. This new way of stretching might also be applicable to the precursors of other conjugated polymers.