Random cross-linked poly(styrene-co-maleic anhydride): Characterization of cross-linking intermediates by size exclusion chromatography

摘要

The cross-linking reaction of poly(styrene-co-maleic anhydride) (SMA) with ethylene glycol (EG) was monitored using size exclusion chromatography. On-line viscosity and static light scattering detection provided [eta] and R-g for structural analysis of the cross-linking intermediates. With increasing reaction time a decrease of the expansion exponent alpha of the Kuhn-Mark-Houwink-Sakurada relationship was observed. A change from coiled structures to spherical molecules during the cross-linking reaction was confirmed by analyzing the fractal dimensions of the molecules after different reaction times. The calculation of the branching parameters g and g' revealed the formation of contracted branched molecules. The connection of SMA chains by EG leads to a contraction of the polymers with increasing molecular weight.