Premium
Fluorescence and UV techniques for studying neck growth and equilibration processes during latex film formation
Author(s) -
Pekcan Önder,
Canpolat Murat,
Arda Ertan
Publication year - 1998
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199812)47:4<451::aid-pi83>3.0.co;2-j
Subject(s) - annealing (glass) , materials science , fluorescence , glass transition , pyrene , analytical chemistry (journal) , void (composites) , activation energy , methyl methacrylate , photochemistry , polymer chemistry , chemical engineering , polymer , chemistry , composite material , copolymer , optics , chromatography , organic chemistry , physics , engineering
Steady state fluorescence (SSF) and UV–visibletechniques have been used to study neck growth and equilibrationprocesses during the coalescence of hard latex particles. Latex filmswere prepared separately by annealing pyrene (P y )labelled and unlabelled poly(methyl methacrylate)(PMMA) particles above their glass transition temperature.During the annealing processes, the optical clarity of the filmsincreased considerably. Direct fluorescence emission of excited pyrenefrom labelled latex films was monitored as a function of annealingtemperature to detect this change. Void closure temperature( T c ) and time( t c ) were determined at the point wherethe fluorescence emission intensity became maximal. Below this point,the increase in fluorescence intensity( I op ) against temperature was used todetermine the activation energy for viscous flow(Δ H ≈47kcalmol −1 ). Thedecrease in I op above the void closure temperaturewas used to determine the backbone activation energy(Δ E ≈44kcalmol −1 ) for theinterdiffusing chains. Unlabelled PMMA particles were used to preparefilms for UV–vis measurements. The transmitted photon intensity( I tr ) from these films increased as theannealing temperature was increased. This behaviour was also used todetermine the backbone activation energy(Δ E ≈35kcalmol −1 ) for theinterdiffusing chains. © Society of Chemical Industry.