ISO 11235:2016 specifies the methods to be used for the evaluation of sulfenamide accelerators:
- MBTS: benzothiazyl disulphide,
- CBS: N-cyclohexylbenzothiazole-2-sulfenamide,
- TBBS: N-tert-butylbenzothiazole-2-sulfenamide,
- DIBS: N,N'-diisopropylbenzothiazole-2-sulfenamide,
- DCBS: N,N'-dicyclohexylbenzothiazole-2-sulfenamide,
- MBS: N-oxydiethylenebenzothiazole-2-sulfenamide.
NOTE Although MBTS is not a sulfenamide, it is the primary decomposition product of these accelerators and quantitatively determined by the method specified in 5.2.
The analytical methods are applicable for most commercial sulfenamide accelerators:
- sulfenamides of primary amines (type I),
- sulfenamides of unhindered secondary amines (type II),
- sulfenamides of hindered secondary amines (type III).
The method (5.2) to determine purity by high performance liquid chromatography (HPLC) is the preferred method.