H.-M. Petri, A. Stammer and B. A. Wolf
"Continuous Polymer Fractionation (CPF) of Poly(vinylmethylether) and a new [h]-M-Relation of Methylethylketone"
Macromolecular Chemistry and Physics 1995, 196, 1453-1465.
Abstract: Continuous polymer fractionation (CPF) - a new large-scale method - was applied to the technical poly(methyl vinyl ether) (PVME) using toluene as solvent and petroleum ether as nonsolvent. Two different devices served as fractionation apparatus, namely a column packed with glass beads and a set of mixer-settler extractors. Advantages and draw-backs of these devices are discussed. The experiments yielded numerous PVME fractions, varying in molar mass from 22 to 87 kg/mol and in molecular non-uniformity U = (($) over bar M(w) ($) over bar M(n)) - 1 from 0,25 to 0,41 according to gel-permeation chromatography as compared with ca. U = 1,30 for the starting material. The following Kuhn-Mark-Houwink relation was established for PVME in ethyl methyl ketone at 30 degrees C: [eta]/(mL/g) = 2,6 . 10(-3) ($) over bar M(0,86).

preprint number: 155