Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9694144 | Thermochimica Acta | 2005 | 6 Pages |
Abstract
In this study, sulfonated poly(styrene-isobutylene-styrene) (S-SIBS) block copolymers were characterized by thermogravimetry as a function of four different processing conditions: sulfonation level, annealing temperature, film formation, and casting solvent. Sulfonated samples showed an increase in degradation temperature from 432 to 450 °C compared to the unsulfonated polymer, regardless of sulfonation level or other processing condition. Sulfonated samples also showed an additional minor loss of mass at approximately 290 °C, which was not observed in the unsulfonated polymer. At this temperature, desulfonation or a cleavage reaction of the aromatic carbon-sulfur bond occurs. In addition, annealing the sulfonated block copolymer at a higher temperature (180 °C) for an extended period of time also results in a partial desulfonation. These results were confirmed by a reduction in water sorption and in intensity of the infrared bands associated with sulfonic acid. There was no change in thermal stability in S-SIBS block copolymers as a function of film formation (solvent cast versus heat pressed) and casting solvent (six different solvents).
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
David Suleiman, Yossef A. Elabd, Eugene Napadensky, James M. Sloan, Dawn M. Crawford,