Chain branching detection by Cole–Cole modeling of rheological properties changes during PET mechanical recycling

摘要: Abstract The detection of branched chains in thermally degraded thermoplastic polymers is far from simple, especially at a low conversion ratio, mainly because the sensitivity commonly used laboratory analytical techniques. objective this article to present an approach able demonstrate formation such macromolecular structures during thermal degradation molten PET oxygen partial pressures (typically for lower than 9% atmospheric pressure). Such ageing conditions are met mechanical recycling by extrusion, and can be simply reproduced sequential nitrogen/air tests rheometer cavity. consists careful analysis complex shear modulus changes Cole–Cole diagram. Values obtained model parameter K′ indicate clearly accumulation melt with time residence reactor.