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

Abstract

Light scattering has proved itself an efficient technique to determine particle diameters in heterogeneous dilute dispersions in the micrometer range. Extrusion of polymer blends is expected to give rise to very small particles, typically in the range from hundreds of nanometers to tens of micrometers. A light scattering device developed in OUT laboratory has been used to study the morphology of polymer blends obtained in 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 experimental measurements and theoretical results for dilute systems. Second, we have investigated the effect of shear flow on the droplet deformation. Finally, we have studied the variations of the light scattering pattern for a reactive blend.

The Effect of Post-extrusion Conditions in Ribbon Extrusion of Polymer Blends

“…Then, the initial morphology of the blend (extruder die exit, x = 0) is needed in order to calculate the deformation of each particle under specific postextrusion conditions. Some techniques are now available to extract morphological information from the extrusion process [30]. In our case, extrusion of the blends were performed for DR = 1 and used as a starting point.…”

Reactive Processing of Thermoplastic Polymers: A Review of the Fundamental Aspects

“…The main advantage of this tech-nique is the immediate response obtained without any surface or interface modification occurring during sample preparation by using more conventional technique like electron microscopy. Schlatter et al [335] and Serra et al [336] developed a light scattering device especially designed to be mounted on a twin screw extruder at different locations along the barrel. They obtained light scattering patterns which have been interpreted in relation with variations of the processing parameters.…”

Real time detection of particulate heterogeneities in polymer extrusion processes using microphotometric measuring method

“…Another version uses a bypass set-up combining 3 laser sources at different angles with a CCD detector. 18 Measurements at 3 scattering angles give high sensitivity for small particles and allow a distinction of different kinds of particles. But this method is critical to perform continuous quality investigations because 30 min have to pass to rinse the flow channel before starting a new measurement.…”