Addition of nanosilicas with different silanol content to thermoplastic poliurethane adhesives

J. VEGA BAUDRIT J. M. MARTÍN MARTÍNEZ, P. VÁZQUEZ, V. NAVARRO BAÑÓ

Int. Journal of Adhes. and Adhes.

Elsevier

Año: 2005 vol. 26 p. 378 - 388

ABSTRACT Polyurethanes thermoplastics (TPU?s) adhesives containing fumed silicas with different degree of silanization were prepared and characterized using FTIR spectroscopy, differential scanning calorimetry (DSC), plate-plate rheometry, DMTA, transmission electron microscopy (TEM), mechanical properties and adhesion analysis. In TPU composites, the segmental incompatibility on the TPU was increased with the presence of the hydrophilic nanosilicas. The formation of hydrogen-bonds between soft segments chains from TPU and the silanol groups on the silica surface was favoured. Therefore, TPU became well-organized and consequently crystallinity was increased. The results obtained show that fumed nanosilica improved thermal, viscoelastic and mechanical properties. Likewise, immediate T-peel strength was improved in filled TPU adhesives.