Separating Polymer Solutions with Supercritical Fluids. II. Polystyrene-Toluene-Ethane.

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Abstract:

The effect of supercritical ethane on the high-pressure phase behavior of the polystyrene-toulene system is experimentally investigated. Adding 17.8 wt- ethane to the polystrene-toulene solution lowers the temperature of the lower critical solution temperature LCST curve by 162 C, 22.5 wt- lowers the temperature of the LCST curve by 231 C, and with 24.9 wt- the LCST curve is shifted to such low temperatures that it merges with the upper critical solution temperature UCST curve. In practice this means that polymer solutions can be separated at lower temperatures where thermal degradation of the polymer is less. Also, greater than 99 wt- of the polystyrene is recovered in the polymer-rich phase after the solution phase splits. Preliminary results are reported on the effects of shearing i.e. mixing and polymer entanglementdisentanglement times on the location of LCST and UCST curves in pressure-temperature P-T space. Pattersons correstates treatment is used to model the LCST data. Keywords Polystyrene, Supercritical fluids, Separation, Phase behavior.

Author(s):
Seckner, A. J. ; Mcclellan, A. K. ; Mchugh, Mark A.
Author Organization(s):
JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF CHEMICAL ENGINEERING
Descriptive Note:
Technical rept.,
Pagination:
0032

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
TR-4
Contract/Grant Number(s):
N00014-85-K-0709
 Subject Terms
Communities of Interest:
No COI(s) Identified
Descriptor(s):
*POLYMERS, *POLYSTYRENE, *ETHANES, *TOLUENES, LOW TEMPERATURE, SOLUTIONS(MIXTURES), HIGH PRESSURE, PHASE STUDIES, CRITICAL TEMPERATURE, FOULING, SOLUTIONS(GENERAL), SEPARATION, FLUIDS, SUPERCRITICAL FLOW, BEHAVIOR, THERMAL DEGRADATION
Field(s)/Group(s):
Polymer Chemistry
Keyword(s):
WUNR625859
Report Date:
1987 Feb 24