ISSN:
0887-624X
Keywords:
dithiadiazolium salts
;
initiators
;
polymerization
;
tetrahydrofuran
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Mono-, bis- and tris-(1,3,2,4-dithiadiazolium) salts [R-(CNSNS+)n]n+[AsF-6]n (R = aryl, n = 1, 2, 3) were found to initiate the cationic ring-opening polymerization of tetrahydrofuran (THF) at room temperature to give clear gels from which the pure polymer was precipitated. 1,3,2,4-Dithiadiazolium cations associated with the hard [AsF6]- anion thus constitute a new class of cationic polymerization initiators. The poly(THF) formed by initiation with 1,3,2,4-dithiadiazolium cation was characterized by gel permeation chromatography, infrared spectrophotometry, and 13C-NMR spectroscopy. Number-average molecular weights of 198 700 g mol-1 (polydispersity 1.96) and 190 000 g mol-1 (polydispersity 1.61) were obtained using [PhCNSNS] [AsF6] and [C6H3-1,3,5-(CNSNS)3][AsF6]3, respectively, as initiators. The use of multifunctional dithiadiazolium salts as initiators suggests that they may be useful in the preparation of starburst and dendritic polymers. © 1992 John Wiley & Sons, Inc.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1992.080301219
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