H. J. V. Ramesdonk, M. Vos, J. Verhoeven
May 1, 1987
Citations
1
Influential Citations
41
Citations
Journal
Polymer
Abstract
Abstract The (time-resolved) fluorescence spectra of 1-phenyl-4-(4-cyano-1-naphthylmethylene)piperidine (1) have been measured during the polymerization of methylmethacrylate (MMA). It was found that the fluorescence maximum of 1 shows a large hypsochromic shift as polymerization of the MMA medium progresses. While the emission maximum is located at 565 nm in the monomer, it is found at 450 ± 5 nm in the polymer (PMMA). The polarization of the fluorescence increases strongly during the polymerization, indicating that the rotational motion of 1 ceases on the timescale of the fluorescence lifetime (about 10 ns). Fluorescence measurements performed with a detection time delay with respect to the exciting laser pulse showed that within the time range 0–100 ns the molecule 1 undergoes reorientation and/or internal relaxation even in a PMMA matrix; a red shift of the emission with time occurs, together with a decrease of the degree of fluorescence polarization.