The effects of incorporating fluorinated polyhedral oligomeric silsesquioxane, [F3C(CH2)(2)SiO1.5](n) on the properties of the silicones

摘要

A hydrophobic filler with the siloxane skeleton, fluorinated polyhedral oligomeric silsesquioxane (FPOSS), was incorporated in varying percentages (2.5, 5, and 10 wt%) in a polydimethylsiloxane-alpha,omega-diol (PDMS) of molecular weight 230,000 g/mol, in solution. Some structural characteristics and properties derived from F-POSS (low polarizability, weak intermolecular force, low surface energy), similar to those of polydimethylsiloxane, create prerequisites for good compatibility of these two components and enrichment of some of their features: better mechanical parameters, increased hydrophobicity and lower dielectric constant useful for practical applications such as insulators. The composites processed as films and stabilized by condensative crosslinking of OH ends of PDMS with a tetrafunctional silane were studied in terms of morphology, mechanical properties, hydrophobicity of the surface, and water vapor sorption capacity, optical properties, dielectric behavior, conductivity, and dielectric strength. Results showed that, although the mixing of the two components was made in solution, it did not occur at the molecular level. However, the expected results are achieved except the hydrophobicity which is not affected noticeable. (C) 2017 Elsevier B.V. All rights reserved.