Products & Applications
Tulco offers a comprehensive portfolio of surface modified precipitated silica products to support a wide range of applications and performance requirements. Below you will find a list of our available products. Technical data sheets are available upon request and provide detailed information on physical and chemical properties, recommended uses, handling guidance, and performance characteristics.
For technical data sheets, additional product information, or application support, please contact Tulco directly.
HMDS / HMDZ Treated Hydrophobic Silica
Tulco Inc develops HMDS treated hydrophobic precipitated silica designed for applications where moisture resistance, powder flow, and compatibility with organic systems are critical. By modifying the silica surface with hexamethyldisilazane, surface silanol groups are replaced with trimethylsilyl functionality, creating a highly hydrophobic and organophilic material.
With more than fifty years of experience in silica surface modification, Tulco supports formulators working across coatings, elastomers, adhesives, and powder systems. Tulco products are engineered to deliver consistent performance, reliable dispersion, and predictable behavior in both processing and end use environments.
What Makes HMDS Treated Silica Different
HMDS treated precipitated silica combines the structural benefits of precipitated silica with a highly hydrophobic surface.
This results in:
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strong moisture resistance
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improved compatibility with organic resins and polymers
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reduced water adsorption
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enhanced powder flow and handling
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controlled rheology without excessive thickening
Compared to other silica types, HMDS treated silica offers a balance between performance and processability. It delivers hydrophobic functionality without the aggressive thickening behavior commonly seen with fumed silica.
Key Applications
Powder Flow Aids and Anti Caking
One of the most effective uses of HMDS treated silica is in dry powder systems.
Used in:
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powdered resins
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powdered coatings
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powdered metals
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pigments and specialty chemicals
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Performance benefits:
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prevents caking in humid environments
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reduces interparticle friction
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improves flowability and handling
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maintains consistent dosing and processing
The hydrophobic surface minimizes moisture uptake, allowing powders to remain free flowing during storage and transport.
Powder Coatings
HMDS treated silica performs well as a post blend additive in powder coating formulations.
Benefits include:
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improved fluidization
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enhanced electrostatic spray performance
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reduced clumping during storage
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better transfer efficiency during application
These properties support consistent coating quality and improved processing efficiency.
Silicone Rubber and RTV Systems
In silicone elastomers, HMDS treated silica functions as a reinforcing and processing aid.
Used in:
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RTV sealants
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silicone adhesives
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silicone rubber compounds
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Performance benefits:
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viscosity control
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improved extrusion behavior
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enhanced moisture resistance
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better compatibility with siloxane systems
This allows formulators to maintain performance while improving processing stability.
Plastics and Polymer Systems
HMDS treated silica is used in thermoplastics and masterbatch formulations.
Applications include:
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polyolefins
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PVC compounds
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additive masterbatches
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Benefits:
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anti blocking in films
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improved slip properties
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better dispersion during compounding
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reduced sensitivity to moisture
Adhesives and Sealants
HMDS treated silica provides hydrophobic functionality in adhesive and sealant systems without excessive viscosity build.
Used in:
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polyurethane adhesives
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hybrid polymer sealants
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construction adhesives
Functions:
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anti settling support
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moderate rheology control
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improved moisture resistance
It is often selected when formulators need balance between flow and stability.
Agricultural and Chemical Powders
In industrial and agricultural powders, HMDS treated silica acts as a carrier and flow aid.
Used in:
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agricultural formulations
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catalysts
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powdered additives
Benefits:
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prevents clumping in humid environments
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improves handling and transport
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supports consistent application performance
Performance Positioning
Compared to other silica technologies:
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Hydrophilic precipitated silica focuses on absorption and reinforcement
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HMDS treated precipitated silica excels in hydrophobic powder flow and compatibility
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PDMS treated silica is commonly used for slip and surface effects
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Hydrophobic fumed silica delivers strong rheology and anti sag performance
HMDS treated silica fills a critical middle ground by offering hydrophobic performance with easier processing and lower cost.
Tulco as a HMDS Treated Silica Supplier
Tulco is a global silica supplier supporting manufacturers who require consistent, high performance hydrophobic silica materials.
With more than fifty years of experience, Tulco works closely with formulators to deliver treated silica that meets exact specifications for each application. Our team understands the importance of consistency, batch to batch reliability, and on time delivery in production environments.
Tulco coordinates logistics through dedicated transportation systems to ensure material arrives when it is needed. Whether supporting large scale manufacturing or specialized formulations, Tulco provides dependable supply, responsive technical support, and the ability to produce custom treated silica solutions tailored to your process.
Work With Tulco
HMDS treated hydrophobic precipitated silica is a versatile solution for improving powder behavior, moisture resistance, and formulation performance across a wide range of industries.
Contact Tulco to discuss your application, request technical data, or develop a custom treated silica solution tailored to your formulation.
