What is ISO 7725 about?
ISO 7725 discusses rubber and rubber products. ISO 7725 specifies methods for the determination of chlorine and/or bromine present in raw rubber as well as vulcanized or unvulcanised rubber compounds.
The methods are applicable to natural rubbers and to the following synthetic rubbers: isoprene, styrene-butadiene, butadiene, butyl, halogenated butyl, nitrile, ethylene-propylene, chloroprene and epichlorohydrin.
Who is ISO 7725 for?
ISO 7725 on determining chlorine and bromine content in rubber and rubber products is useful for:
- Rubber farmers
- Tire manufacturers
- Manufacturers of hoses
- Manufacturers of adhesives
Why should you use ISO 7725?
Chlorine and bromine, when introduced to any type of rubber (raw, vulcanized, unvulcanised), tend to increase the adhesion quality of the rubber. They also result in faster curing of rubber products. There are multiple methods to determine chlorine and bromine content in rubber compounds.
ISO 7725 provides you with two methods for determining chlorine and bromine content in rubber compounds. Ion chromatography and potentiometric titration methods are applicable for raw, vulcanized and unvulcanised rubber compounds. ISO 7725 provides you with the apparatus and procedures for both these methods and also the formula to determine chlorine and bromine for each method.
With ISO 7725 you can identify the surplus or deficit content of chlorine or bromine in your rubber products.
What’s changed since the last update?
BS ISO 7725:2020 replaces ISO 7725:1991, which has been technically revised. The main changes in BS ISO 7725:2020 compared to ISO 7725:1991 are as follows:
- The ion chromatography method has been added in Clause 6
- The titration procedure has been improved in Clause 7
- The tubular furnace combustion method for sample preparation has been added in Annex A
- The oxygen combustion flask method for sample preparation has been improved in Annex B
- The oxygen combustion bomb method for sample preparation has been added in Annex C
- Mercury nitrate and hydrazine are no longer used due to their hazardous properties
