Organically-modified silica based microspheres for self-curing polyurethane one component foams

Hybrid organosilica microspheres (MSs) doped with aqueous glycerol are tested as enablers for self-curing polyurethane one-component foams (OCF). The MSs have been characterized by Scanning Electron Microscopy, Fourier Transformed Infrared Spectroscopy, Thermal Gravimetric Analyses and leaching test. Shaking rate, of the pre-polymer inside the aerosol can, and curing speed tests of the sprayed foam, in a low moisture environment, were performed in order to evaluate the effect of the MSs on the OCF can's lifespan, as well as their contribution to the PU foam's curing process. The organic functionality of these silica-based MSs (methyl and glycidyloxy groups) was found to be responsible for a reduced leaching and low water absorption tendency, which is critical for a longer shelf life of the product required for commercial applications. In addition, the methyl functional MSs presented a significant increase in the curing rate of the PU foam.