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A fluorescence study on critical exponents during sol‐gel phase transition in complex monomeric systems
Author(s) -
Kaya Demet,
Pekcan Önder
Publication year - 2003
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200351217
Subject(s) - percolation (cognitive psychology) , gel point , monomer , critical exponent , phase transition , fluorescence , pyrene , methacrylate , materials science , methyl methacrylate , polymer , polymerization , critical point (mathematics) , copolymer , polymer chemistry , phase (matter) , transition point , percolation theory , analytical chemistry (journal) , chemistry , thermodynamics , chromatography , organic chemistry , physics , optics , composite material , biology , conductivity , mathematical analysis , mathematics , neuroscience
Abstract Methyl methacrylate (MMA), ethyl methacrylate (EMA) and various combinations of MMA with EMA were used during FCC experiments. Pyrene (P y ) was introduced as a fluorescence probe and fluorescence lifetimes from its decay traces were measured during sol‐gel phase transitions. The fast transient fluorescence (FTRF) technique was used to study the critical exponents during sol‐gel phase transition in free‐radical crosslinking copolymerization (FCC). The results were interpreted in the view of percolation theory. The critical exponents of gel fraction, β and weight average degree of polymerization, γ were measured near the point of gel effect and found to be around 0.37 ± 0.015 and 1.69 ± 0.05 in all systems studied respectively.