Premium
Macromolecule Crosslinking and Scission Yield Determination from Sol‐Gel Analysis Using a Log–Log Scale Method
Author(s) -
Shyichuk Alexander,
Shyichuk Irena
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020101)203:2<401::aid-macp401>3.0.co;2-2
Subject(s) - macromolecule , dispersity , logarithmic scale , logarithm , yield (engineering) , molar mass distribution , intersection (aeronautics) , materials science , chemistry , polymer chemistry , analytical chemistry (journal) , mathematics , polymer , chromatography , organic chemistry , physics , composite material , mathematical analysis , biochemistry , acoustics , engineering , aerospace engineering
Sol‐gel analysis is known as a convenient method to evaluate macromolecule crosslinking efficiency. Quantitative results can be obtained by plotting the logarithm of the sol fraction ( s ) vs. the logarithm of the crosslinking index ( CI ). The gel‐point value is determined as the intersection with the horizontal line at log ( sol ) = 0, and the sciss/cross ratio is determined from the slope of the plot. The number of crosslinks per initial macromolecule at the gel‐point is pre‐known as a function of the polydispersity index and the sciss/cross ratio, and from this both crosslinking and scission yields are calculated. This report contains graphs needed for the determination of crosslinking efficiency for narrow ( M̄ w / M̄ n = 1.5) and broad ( M̄ w / M̄ n = 5) molecular weight distributions. An example of radiation crosslinking of low‐density poylethylene is also presented.