Design and Optimization of Precipitated Silica for Reinforcing Rubber

1. Design and Optimization of Precipitated Silica for Reinforcing Rubber Chetan Suryawanshi, Chunyan Chen and Dale W. Schaefer, Department of Materials Science & Engineering University of Cincinnati, Cincinnati, OH 45221-0012, Peyman Pakdel Bridgestone/Firestone Inc 1200 Firestone Parkway Arkon, OH 44317-0001 Lou Gatti J.M Huber Corporation 907 Revolution Street P.O Box 310 Havre De Grace, MD 21078 Jan Ilavsky National Institutes of Standards and Technology Advanced Photon Source Argonne National Labroratory, 9700 South Cass Avenue Argonne, IL 60439 Peter R. Jemian University Of Illinois At Urbana-Champaign Advanced Photon Source Argonne National Labroratory, 9700 South Cass Avenue Argonne, IL 60439

2. Reinforced Elastomers 1 m Surface Treatment Polymer Additives Filler Mastication Forming Flame or Solution Synthesis

3. 0.1m Structural Complexity 10m What Controls agglomerate size? When do they form? What controls fragility? Agglomerates 1m How does Silica/Carbon Reinforce? What is the optimum structure? Aggregates What controls aggregate size? What is the optimum size What is the optimum primary? Are the primaries porous? What controls primary size? Primary Particles

4. Morphology From Scattering Agglomerate Aggregate Primary Particle Network Polymer 100,000 nm 200 nm 10 nm 0.5 nm

5. + + Powder Synthesis • Parameters affecting silica polymerization • Temperature • pH • Time • Ionic strength • Shear due to agitation Polymerization Nucleation Growth Aggregation Aging Agglomeration

6. In Situ Growth UNICAT USAXS

7. Stabilization Techniques Electrostatic Stabilization Steric Stabilization

8. Silicic Acid Neutralization

9. Morphology of Modified Protocols Solution Powder

10. Agglomerate Evolution Electrostatic Steric Early Slurry Dry Powder Late Slurry

11. Comparison of Powder and Rubber Dispersion

12. Mechanical Properties

13. Filler dispersion in rubber