Transparent and Flexible Films of Thermoplastic Polyurethanes Incorporated by Nano-SiO₂ Modified With 4,4′-Methylene Diphenyl Diisocyanate

Abstract

4,4′-Methylene diphenyl diisocyanate (MDI) played a dual role for preparing thermoplastic polyurethanes (TPU)/silica nanocomposites; both as monomer to synthesize MDI-capped poly(tetramethylene oxide) (PTMO) and as surface modifier of nano-SiO₂ particles. Untreated and/or MDI-treated SiO₂ were homogeneously incorporated into the resulting TPU polymer after extension of the chains by 1,4-butanediol (BDO). To modify silica nanoparticles, MDI was grafted to the surface silanol groups of the nanoparticles by forming urethane links. MDI-treated SiO₂ (SiO₂-MDI) nanoparticles, as well as TPU/untreated SiO₂ (TPU/SiO₂) and TPU/MDI-treated SiO₂ (TPU/SiO₂-MDI) nanocomposites were characterized by FT-IR, UV-vis DRS, XRD, SEM, mechanical, and thermal analyses.

GRAPHICAL ABSTRACT

Keywords:

• Nanosilica
• polyurethane-based nanocomposite
• surface modification
• UV-vis DRS

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gpom.