Thermal properties and processability of dialkoxy-PPV precursors

A homologous series of ring-substituted dialkoxy-PPV precursors have been synthesized and characterized. By increasing the number of methylene units in the side groups up to six, a linear decrease of the glass transition temperature is found, with a span of ca. 100 degrees C, going from 92 degrees C down to -11 degrees C. T.m.a. experiments reveal high stretchability of thin films at temperatures just above T-g without elimination. The thermal conversion of the precursor polymer into the conjugated materials was studied and with controllable amounts of catalytic acid in the thin films, a well-defined processing window can be established in order to prepare stretched, conjugated thin films of dialkoxy-PPV material. Copyright (C) 1996 Elsevier Science Ltd.