Silane-modified polymers are designed to combine the strength of polyurethanes with the weathering resistance of silicones.1 In addition to their high-performance properties, these hybrid polymers are achieving popularity due to their solvent- and isocyanate-free nature.2 Sealants based on hybrid polymers also provide good over-paintability, stain resistance, and primerless adhesion to a wide range of substrates.
In silane-modified sealants, the mineral component can represent over 60 wt% of a commercial formulation. The choice of mineral therefore has an impact on the processing and ultimate performance of the sealant. Many mineral types are used in sealants and adhesives for applications including construction and glazing, transportation, and DIY. For example, engineered calcium carbonates are used to modify rheological and mechanical properties to address the correct cost/performance ratio applicable for the relevant application. Maximizing the inorganic content and minimizing the organic binder content is a common trend in such compounds.