BS ISO 11235:2023 - Page 2

Rubber compounding ingredients. Sulfenamide accelerators. Test methods. | Status: Current

1 Scope This document 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 1 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).

NOTE 2 Classification and key properties of sulfenamide accelerators are described in Annex A.

The method (5.2) to determine purity by high performance liquid chromatography (HPLC) is the preferred method.