DSC PICTURE OF A POLYMER BLEND CARCASS

Differential scanning calorimetry (DSC) was used to view the extent of mixing in polymer blends as a function of extrusion parameters and po sition on the screw. Blends of (a) two amorphous polymers and (b) one amorphous and one semi-crystalline polymer were studied. The ability t o quench cool the extruder yields a carcass representing the mixing pr ocess. DSC was used to measure segment by segment changes in transitio n temperatures throughout a carcass. Overlaying DSC scans provide a pi cture of mixing process. Microscopy was used to corroborate these obse rvations. This technique is useful in evaluating and optimizing extrus ion compounding operations.