Photochemical behaviour of poly(organophosphazenes)—Part VIII. Further investigations on the sensitized photochemistry of poly[bis(4-isopropylphenoxy)phosphazene]

✍ Scribed by M. Gleria; F. Minto; P. Bortolus; W. Porzio; S.V. Meille

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 475 KB
• Volume: 26
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(90)90247-2

✦ Synopsis

The photochemistry of poly[bis(4-isopropylphenoxy)phosphazene] (PIPP) sensitized by hexakis(4-benzoylphenoxy)cyclophosphazene and by poly[bis(4-benzoylphenoxy)phosphazene] was investigated both in solution and in film. Air-equilibrated CH2CI 2 solutions of this polymer, also containing the above-mentioned benzophenone-containing phosphazene substrates, were irradiated with light absorbed exclusively by the carbonyl substituent. The irradiation causes a sharp decrease of the viscosity, attributed to chain scission of the PIPP backbone. In this process the solvent plays a key role. On the other hand, no photochemical change was observed for the same pair of molecules in the solid state. X-ray diffraction studies and DSC investigations on PIPP films, doped with benzophenone-substituted cycloor poly-phosphazenes, reveal that the lack of photoreactivity is due to phase segregation in these systems.