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Analysis of the molecular weight distribution in free radical polymerization: Modelling of the MWD from the analysis of experimental GPC curves
Author(s) -
Maschio Giuseppe,
Scali Claudio
Publication year - 1999
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/(sici)1521-3935(19990701)200:7<1708::aid-macp1708>3.0.co;2-3
Subject(s) - deconvolution , molar mass distribution , gel permeation chromatography , polymer , polymerization , radical polymerization , chemistry , polymer chemistry , thermodynamics , organic chemistry , algorithm , mathematics , physics
In this paper different techniques for the deconvolution of experimental gel permeation chromatography (GPC) curves of polymers obtained from batch reactors are examined with the aim of improving the modelling of the polymerization process. The deconvoution of the GPC curves gives insight into the effects of diffusive phenomena on the values of the average molecular weights ( M n and M w ) and the molecular weight distribution ( MWD ) of the polymer. Two methods, one based on a two‐peak deconvolution and the other one based on a multi‐peak deconvolution, are compared. The different characteristics and relative merits of the two methods are illustrated using several sets of experimental data. In conclusion, the first method is less accurate but allows a separation of the two contributions given by the chemical and diffusive control of the MWD ; the second method has a sound theoretical background (confirms the prediction of the free volume theory) and is potentially much superior but the results prove to be more sensitive to the quality of the experimental part.