Photophysical Processes in Polymers. III. Properties of Triplet Energy Traps in 1-Vinylnaphthalene Copolymers

Abstract

Emission spectra of two‐component atactic copolymers of 1‐vinylnaphthalene with styrene (PVN/S) and with methylmethacrylate have been investigated in a glassy matrix at 77°K. In PVN/S, the rate of intramolecular triplet energy transfer through segments derived from styrene exceeds that of intermolecular triplet transfer from polystyrene to piperylene; the migration occurs through chains having as many as 140 styrene‐derived units. Radiative triplet depletion within the 1‐vinylnaphthalene‐derived segments is manifested by (1) phosphorescence originating from units near the ends of the segments, and (2) delayed fluorescence due to free triplet annihilation within the segment, although some trapping may also take place. In contrast, delayed fluorescence from poly(1‐vinylnaphthalene) appears to result from several annihilation reactions, and serves to demonstrate fundamental differences between the homopolymer and copolymer.