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A line of polymethylmethacrylate (PMMA) samples was synthesized using synchrotron radiation of the VEPP-3 accelerator and the high-energy electron beam of the ILU-6 accelerator. The study was carried out during the in situ synthesis of PMMA in the recording of luminescence spectra and their kinetics. An experimental study was also made of the luminescence of PMMA samples with a molecular weight in the range 0.2 · 10^6 - 6 · 10^6 under excitation by an SR beam in the range of 3 - 60 keV. It was found that with an increase in the molecular weight of PMMA, the maximum of the luminescence band of PMMA shifts toward the long-wavelength direction (redshift), and the luminescence decay time decreases. An increase in the luminescence bandwidth with increasing molecular weight is also observed. These effects are explained by the ordering of the polymer structure and increase in density, which leads to a decrease in interatomic distances and, consequently, to a shift in electronic levels and a change in their width.
This work was supported by RFBR grants 19-29-12045, 16-29-01050, 14-03-00770 and the Ministry of Science and Education of Russia grant AAAA-A17-117030310280-6.
