Premium
A proposed method for estimating polymer molecular weight distribution without fractionation
Author(s) -
Rehner John
Publication year - 1960
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1960.070041015
Subject(s) - dispersity , polymer , molar mass distribution , polystyrene , materials science , fractionation , divinylbenzene , distribution function , distribution (mathematics) , yield (engineering) , thermodynamics , biological system , polymer chemistry , mathematics , chemistry , chromatography , composite material , physics , copolymer , styrene , mathematical analysis , biology
A method is proposed for estimating rather simply and with relatively little experimental data the molecular weight distribution characteristics of any crosslinkable polymer which follows the Tung distribution function. This function is combined with a fundamental relationship from the statistical theory of sol–gel ratios in randomly crosslinked polymers, to yield a result which relates explicitly the sol‐gel ratio, the crosslink density, and the molecular weight distribution parameters. These parameters give the various average molecular weights and the polydispersity by simple computation. The method has been tested with meager data available for a peroxide‐cured SBR and a divinylbenzene‐crosslinked polystyrene. Reasonably satisfactory results were obtained. A critical test of the absolute accuracy of the method requires experimental data not now available, and some refinements may eventually have to be made. However, the method should be useful, in its present state, for estimating distribution characteristics and, especially, for comparative studies within a given polymer system.