Photodegradation of some luminescent polymers

The photodegradation of four para-phenylenevinylene and two para-phenylene- ethynylene polymers is investigated in neat films and blended polystyrene f ilms. The monomeric photodegradation yield, phi(D,m), due to cw light excit ation at some excitation wavelengths is determined by transmission measurem ent and numerical data analysis. The temporal developments of the optical d ensity spectra indicate inhomogeneous absorption changes. The monomeric pho todegradation yield is of the order of phi(D,m), approximate to 10(-3) to 1 0(-4) for the investigated para-phenylene-vinylene polymers and of the orde r of phi(D,m), approximate to 10(-5) to 10(-6) for the studied para-phenyle ne-ethynylene polymers. (C) 1999 Elsevier Science B.V. All rights reserved.