Ultrasil Precipitated Silica:

• Used as a reinforcing filler
• Silica grades pre-reacted with silane available
• The use of precipitated silicas without silane additives produces improved dynamic properties; however, mixture viscosity, vulcanization time, and crosslinking density all suffer
• Organosilanes help the silica bond to the polymer, improve processability and produce very good static and dynamic rubber technological properties

Organosilanes:

• Generally bifunctional organic silicon compounds with two reactive groups
• Grades include Si69, Si264, Si266, and X50S
• Imparts better tensile strength
• Reduces heat build-up
• Improves abrasion resistance
• Reduces compression set
• All sulfur-functional silanes from Evonik are available in liquid form; some are also available in dry blend with carbon black or as a pre-reacted silica compound