Online light scattering measurements: a method to assess morphology development of polymer blends in a twin-screw extruder

摘要

Light scattering has proved itself an efficient technique to determine particle diameters in heterogeneous dilute dispersions in the micrometer range.Extrusion of polymer blendsis expected togive rise to very small particles,typically in the range from hundreds of nanometers to micrometers.A light scattering device developed inour laboratory has been used to study the morphology of polymer blends obtainedin a twin-screw extruder.The main advantage of this technique is the immediate response obtained without any surface or interface modification that can occur during the sample preparation by using more conventional techniques like electron microscopy.To show the possible applications of this light scattering device,preliminary tests have been carried out.First,we present a comparison between experimentalmeasurements and theoretical results for dilute sytems.Second,we have investigated the effect of shear flow on the droplet deformation.Finally,we have studied the variations of thelight scattering pattern for a reactive blend.