ISSN:
0449-296X
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The results of our studies show that it is possible to depolymerize polysulfide polymers with a nominal sulfur content in excess of 2 per segment of polymer, without previous desulfurization, in order to obtain disulfide polymers. For this purpose it is necessary to take larger amounts of sodium dithionite per segment of polymer, than with a disulfide polymer, to obtain approximately the same of the average molecular weight of the depolymerized product. It is also possible to complete depolymerization with an amount below 2 moles of sodium hydroxide per mole of sodium dithionite, though the upper limit of the ratio of Na2S2O4 to NaOH, at which depolymerization occurs, remains unchanged, i.e., 1:4. During the depolymerization reaction the occurrence of larger or smaller amounts of hydrosulfide, depending on the labile sulfur content, as well as the change of the color of the reaction dispersion, first white, then bright yellow or gray, thereafter white again and, finally, dingy pink, was observed. The reaction, representing in the best way the optimum conditions of depolymerization and the actual relations in the reaction system, is proposed.
Additional Material:
6 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1972.150100905
