Pulse radiolysis studies of poly(methyl methacrylate) containing pyrene

✍ Scribed by M. Szadkowska-Nicze; J. Mayer

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 342 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199806)36:8<1209::aid-pola2>3.0.co;2-v

✦ Synopsis

A pulse radiolysis study of poly(methyl methacrylate) in the presence of pyrene has been carried out in the temperature range 100-295 K. The concentration of pyrene was changed from 10 03 to 10 01 mol dm 03 . The absorption/emission spectra and kinetics of solute excited states and solute radical ions were investigated. It was found that pyrene excited states were formed as a result of their radical ion recombination in a time scale up to seconds. The decay of solute radical ions was influenced by photobleaching and can be described by a time-dependent rate constant. The activation energy of Py ions decay was temperature dependent and was equal to 35.7 and 1.2 kJ/ mol for temperatures úT g and õT g , respectively, where T g Ç 175 K represented the transition temperature responsible for g-relaxation. The reaction mechanism was proposed.