Comparing TESPT dosages by active silane in silica-filled rubber

Can TESPT and TESPD be exchanged at equal weight?

Carrier-based grades supply different amounts of active silane. Silanes with different sulfur ranks also require separate evaluation.

Fix the silica loading and adjust active silane

Keep silica and base rubber constant. Record the active silane basis, mixing sequence and dump condition. Compare agglomeration and cure curves separately to distinguish dispersion effects from cure changes.

Why do white agglomerates remain after adding silane?

Check filler moisture, dispersion and mixing temperature and time against a reference compound. Silica-filled tire compounds: At equal filler and mixing conditions, compare dispersion, cure curve and dynamic properties. Evaluating carrier-based substitutes: Calculate addition on active silane content and subtract the corresponding carrier from the formulation.

Checking Active silane and Total sulfur

Active silane (% by mass): Distinguish neat, carrier-based and blended products. Total sulfur (% by mass): Record the supplier’s description of the sulphur-chain distribution in the product. Volatiles or free alcohol (% by mass): Confirm the test method against the specification for the offered grade.

What to record

• Silane form
• Active quantity
• Mixing sequence
• Agglomeration
• Cure curve

Technical references

• Evonik Si 69: sulfur-containing silane for rubber ↗

Products and processes