Polysulfone (PSU) has been processed into powder form by ball milling, rotor milling,\nand spray drying technique in an attempt to produce new materials for Selective Laser Sintering\npurposes. Both rotor milling and spray drying were adept to make spherical particles that can be used\nfor this aim. Processing PSU pellets by rotor milling in a three-step process resulted in particles of\n51.8 �¼m mean diameter, whereas spray drying could only manage a mean diameter of 26.1 �¼m. The\nresulting powders were characterized using Differential Scanning Calorimetry (DSC), Gel Permeation\nChromatography (GPC) and X-ray Diffraction measurements (XRD). DSC measurements revealed\nan influence of all processing techniques on the thermal behavior of the material. Glass transitions\nremained unaffected by spray drying and rotor milling, yet a clear shift was observed for ball\nmilling, along with a large endothermic peak in the high temperature region. This was ascribed\nto the imparting of an orientation into the polymer chains due to the processing method and was\nconfirmed by XRD measurements. Of all processed powder samples, the ball milled sample was\nunable to dissolve for GPC measurements, suggesting degradation by chain scission and subsequent\ncrosslinking. Spray drying and rotor milling did not cause significant degradation.
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