Easy to process, simple to apply 

Rheology relates to the flow properties of materials, including their viscosity, elasticity, and deformation behavior. These properties can alter when the temperature, pressure, or tension changes. In adhesives and sealants, rheology affects the ease with which an end product can be handled, how well it adheres and its performance in general. 

For example, reducing viscosity can improve formulation processability and handling at higher shear rates and allow higher filler contents for example, to increase thermal conductivity. At low shear rates, in turn, increasing viscosity can improve the anti-sagging and anti-settling properties of formulations. 

The rheology of adhesives and sealants can be modified using silanes – the viscosity is altered, while their flow properties improve. Rheology modifiers assist when formulating, transporting, storing, and using adhesives or sealants, as well as helping to ensure a more durable bond. 

This makes them important for formulators and end users alike: The formulator can adjust special product properties, for example, higher thermal conductivity through higher filling grades. Silanes from Evonik’s Dynasylan® product portfolio can be used efficiently, while adhesives or sealants with good rheological properties are also more durable. 

In turn, the end user benefits from an easier application, faster drying, and improved performance. Like silanes for adhesion promotion, crosslinking, or dispersion, silanes used as rheology modifiers help improve the quality of an adhesive or sealant. 

Evonik offers a wide range of rheology modifiers. For instance, Dynasylan® 4148 is used to control rheological properties and reduce viscosity in highly filled polymer systems, such as polyesters filled with aluminum trihydroxide or thermal interface management systems. 

Evonik provides manufacturers and users with solutions individually tailored to their needs; the silane experts also advise them on handling and using silanes correctly. In addition, the range of services includes fast and reliable delivery of products of the very highest quality. 

• Make adhesive and sealant formulations quick and easy to process 
• Higher storage stability 
• Higher filler loading is possible to improve properties (e.g., higher thermal conductivity) and reduce costs 
• Adhesives and sealants are easy to apply and show improved sagging properties 
• Improved filler dispersion 
• Controlled rheological properties 
• Improved wet-out between resin and filler 
• Very good performance