TY - JOUR
T1 - Universal behaviour of glass transition exponents in various polymeric systems
AU - Pekcan, Onder
AU - Kaya, Demet
PY - 2005
Y1 - 2005
N2 - The fast transient fluorescence (FTRF) technique was used to study the critical exponents during glass transition in free-radical cross-linking copolymerization (FCC). Methyl methacrylate (MMA), ethyl methacrylate (EMA) and various combinations of MMA with EMA were used during FCC experiments. Pyrene (Py) was used as a fluorescence probe and its fluorescence lifetimes from its decay traces were measured during glass transition. Changes in the viscosity of the pre-gel solutions due to glass formation dramatically increased the Py fluorescent lifetimes, which were used to study the glass transition of MMA, EMA and their mixtures as a function of time, at various temperatures and monomer concentrations. The results were interpreted in the view of percolation theory. The critical exponents, β and γ, were measured near the glass transition point and found to be around 0.37 ± 0.015 and 1.69 ± 0.05, respectively, in all systems studied, which are in good agreement with the static percolation results.
AB - The fast transient fluorescence (FTRF) technique was used to study the critical exponents during glass transition in free-radical cross-linking copolymerization (FCC). Methyl methacrylate (MMA), ethyl methacrylate (EMA) and various combinations of MMA with EMA were used during FCC experiments. Pyrene (Py) was used as a fluorescence probe and its fluorescence lifetimes from its decay traces were measured during glass transition. Changes in the viscosity of the pre-gel solutions due to glass formation dramatically increased the Py fluorescent lifetimes, which were used to study the glass transition of MMA, EMA and their mixtures as a function of time, at various temperatures and monomer concentrations. The results were interpreted in the view of percolation theory. The critical exponents, β and γ, were measured near the glass transition point and found to be around 0.37 ± 0.015 and 1.69 ± 0.05, respectively, in all systems studied, which are in good agreement with the static percolation results.
KW - Critical exponents
KW - Fluorescence
KW - Glass transition
KW - Polymer
UR - http://www.scopus.com/inward/record.url?scp=27844495864&partnerID=8YFLogxK
U2 - 10.1163/1568554054915192
DO - 10.1163/1568554054915192
M3 - Article
AN - SCOPUS:27844495864
SN - 0927-6440
VL - 12
SP - 501
EP - 521
JO - Composite Interfaces
JF - Composite Interfaces
IS - 6
ER -