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8357674 
Journal Article 
Polymer melt devolatilization mechanisms 
Albalak, RJ; Tadmor, Z; Talmon, Y 
1990 
Yes 
AIChE Journal
ISSN: 0001-1541
EISSN: 1547-5905 
36 
9 
1313-1320 
English 
Scanning electron microscopy (SEM) was used to study the mechanism of falling‐strand devolatilization of polymer melts. Polystyrene and low‐density polyethylene were enriched with styrene and hexane, respectively, and were subsequently extruded as thin strands at various conditions. The polymer strands were exposed to superheat conditions for preset periods of time ranging from tenths to tens of seconds. The strands were then frozen, fractured, and studied by SEM. Devolatilization was found to proceed through a blistering mechanism, both on the surface of the strands and on the surfaces of volatile bubbles formed within the core of the melt. At all volatile concentrations surface blistering and foaming preceded bubble growth in the core, and occurred before the strands foamed. A mechanism for the observed polymer melt devolatilization is proposed. Copyright © 1990 American Institute of Chemical Engineers