S-80 Predispersed Rubber Chemicals

Function: Curing agent for all natural and synthetic rubbers

S-80, a predispersed sulfur rubber additive, is a masterbatch consisting of 80% elemental sulfur pre-incorporated into 20% polymeric carriers including EPDM and EVM. This product presents as yellow granules, with a specific gravity ranging from 1.96 to 2.07 g/cm³ and a melting point of 112.8–119.3 ℃. It is soluble in carbon disulfide, carbon tetrachloride and benzene, practically insoluble in water, and sparingly soluble in ethanol and diethyl ether.

S-80 delivers excellent dispersibility in rubber formulations. It shortens mixing cycles and exhibits superior compatibility with rubber compounds. Being dust-free, it optimizes workplace conditions and supports automated weighing processes. Its low material loss during processing stabilizes batch-to-batch consistency, reducing reject rates and raw material waste.

S-80 functions as a curing agent suitable for all natural and synthetic rubbers. It enables fast incorporation into rubber mixes and achieves superior sulfur dispersion. Its uniform distribution within the rubber matrix prevents localized over-vulcanization, thereby boosting resistance to aging and dynamic fatigue. Such excellent sulfur dispersion offers distinct benefits for soft rubber compounds, in which homogeneous sulfur distribution is typically challenging.

The dosage is the same as with non-elastomer-bound sulphur. A higher dosage according to the sulphur content is, due to the better dispersion, usually not necessary.

Soft compounds: bright-coloured compounds that have to be free of sulphur stains, rubber articles which have to withstand dynamic stress.

25 kg paper bag

In original closed containers under cool and dry conditions max. 2 years.

2 years

1. What advantages does S-80 show especially for soft rubber compounds? 

Uniform sulfur distribution is hard to realize in soft formulations with low crosslink density. S-80 realizes homogeneous sulfur dispersion in the rubber matrix and prevents localized over-vulcanization. It improves ageing resistance and dynamic fatigue performance, and avoids sulfur blooming and sulfur stains on bright-colored soft rubber products.

2. Can S-80 be used for bright-colored rubber articles and avoid sulfur staining? 

Yes, it is a recommended grade for bright-colored, stain-free rubber compounds. Its pre-dispersed structure suppresses sulfur migration and surface blooming, which effectively eliminates sulfur stains on finished bright rubber goods.

3. Where can I find physiological & toxicological information about S-80? 

Please refer to the corresponding SDS (Safety Data Sheet) for complete physiological, hazard and handling information of this product.

4. Is the dosage of S-80 calculated based on its total weight or only the 80% sulfur fraction? Do I need to raise the addition amount for sufficient curing? 

The effective sulfur content is 80%. You shall calculate the dosage by the pure sulfur fraction. As stated in the TDS, extra higher loading is generally unnecessary even though it is a predispersed form, thanks to its superior dispersion efficiency compared with conventional free sulfur powder.

5. Does S-80 generate dust during weighing and feeding compared with regular sulfur powder? 

S-80 is a predispersed granular product. It is dust-free during operation, suitable for automatic weighing systems, reduces raw material loss and improves workshop hygiene.