An ultraviolet method for the determination of the residence time distribution in a twin screw extruder

Abstract
The stereoselective substitution of chlorine atoms was used to graft anthracene and phenyl groups onto the poly(vinyl chloride) (PVC) backbone as ultraviolet (UV) tracers for the assessment of the residence time distribution (R.T.D) of PVC chains during the extrusion of rigid and plasticized PVC. The residence time distribution obtained using these‐grafted tracers was compared with that obtained using a free UV tracer (anthracene). The polymeric tracer had a narrower R.T.D and a shorter mean residence time. This difference of behavior between a free and grafted tracers was attributed to the compatibility of these tracers with the PVC.