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The reactions of 2‐(4‐morpholinothio)‐ and 2‐(4‐morpholinodithio) benzothiazole in the absence of polyisoprene
Author(s) -
Gradwell M. H. S.,
Hendrikse K. G.,
McGill W. J.
Publication year - 1999
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19990606)72:10<1235::aid-app1>3.0.co;2-o
Subject(s) - benzothiazole , polysulfide , sulfur , chemistry , decomposition , sulfenamide , vulcanization , amine gas treating , polymer chemistry , reaction mechanism , natural rubber , organic chemistry , catalysis , electrode , electrolyte
2‐(4‐morpholinothio)benzothiazole (MOR) and 2‐(4‐morpholinodithio)benzothiazole (MDB) were heated with sulfur and ZnO in a DSC. The products formed at various temperatures were identified and analyzed by HPLC. At temperatures below 200°C, decomposition of the accelerator in the absence of other curatives was slow, degradation products being mainly 2‐bisbenzothiazole‐2,2′‐disulfide (MBTS) and 2‐mercaptobenzothiazole (MBT). A rapid exothermic decomposition above 200°C resulted in the formation of MBT (or its amine salt) and 2‐(4‐morpholino)benzothiazole (MB). MOR and MDB reacted with sulfur to form higher polysulfides. MDB was shown to react more readily with sulfur than MOR and the delayed action of MOR in rubber can therefore not be ascribed to a stable polysulfide as suggested by other authors. Neither MOR nor MDB was found to react with ZnO. A limited reaction between MBT and ZnO was observed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1235–1240, 1999