Synthesis and characterization of polyhedral oligomeric silsesquioxane-based waterborne polyurethane nanocomposites

Abstract

A series of aqueous polyurethane nanocomposites were prepared using various amounts (0.3-4.6 wt%) of a diol functionalized polyhedral oligomeric silsesquioxane (POSS) by the prepolymer mixing method. N,N-bis(2-hydroxy ethyl-2-amino ethane sulfonic acid sodium salt (BES sodium salt) was used as the anionic internal emulsifier and ionic center. The molecular structure of the samples was characterized by ATR-FTIR spectroscopy. We investigated the effect of the POSS contents on the properties of the specimens by particle size and viscosity measurements, X-ray diffractometry, mechanical behavior assessment, dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis and morphological studies. The results showed that with increasing the POSS contents, particle size, viscosity, tensile strength, modulus, Tg, and thermal stability of the synthesized samples were improved. Also, SEM and TEM images indicated that a homogeneous morphology was obtained in the 1.2 wt% POSS-based sample. AFM results showed that the surface roughness increased as the POSS amounts increased.