Synthesis of new superhydrophobic nanosilica and investigation of their performance in reinforcement of polysiloxane

Abstract

We reported a new facile method to synthesize superhydrophobic nanosilica using glycidoxypropyltrimethoxysilane and dodecylamine as treatment agents. Also, we systemically investigate their performance in reinforcement of poly(dimethylsiloxane) (PDMS) rubber. Fourier transform infrared spectrum, contact angle (CA) and thermogravimetric analysis (TGA) measurements were used to characterize the modified nanosilica. Results show that the inherent hydrophilicity of parent nanosilica surface can be greatly altered through this modification method. The CA of as-prepared superhydrophobic nanosilica can reach 160.28. The properties of as-prepared modified nanosilica-filled PDMS composites were systemically investigated by dynamic rheological test, scanning electron microscopy, TGA, dynamic mechanical analysis. These as-prepared superhydrophobic nanosilica exhibit uniform dispersion in the PDMS matrix, and their composites also show good mechanical properties and distinct advantage on thermal stability compared with those of the pure silica-filled PDMS composites. Also described is the probable mechanism for the reinforcement of as-prepared superhydrophobic nanosilica-filled PDMS.

Adjusting the properties of silicone rubber filled with nanosilica by changing the surface organic groups of nanosilica

“…This could explain why the surface modification, and in particular, the in situ surface modification of silica by organic compounds has been extensively focused on [17e19]. For example, by incorporating nano-silica in situ surfacecapped with glycidoxypropyltrimethoxysilane and dodecylamine, Zhang and co-workers significantly improved the mechanical properties and thermal stability of polydimethylsiloxane [18]. Vartika Joshi and co-workers found that the presence of silicasilicone inter-penetrating network accounts for the improved mechanical properties of silicone elastomers filled with fumed silica functionalized by hybrid fillers containing aliphatic and aromatic groups [19].…”

Dynamics heterogeneity in silica‐filled nitrile butadiene rubber

“…The heterogeneities are also reflected by “bound rubber (BdR),” a coherent, viscoelastic network formed by tightly and loosely bound rubber fractions . BdR is considered to be crucial for the processing, rheology, and storage stability of compounds and the mechanical properties of vulcanizates . It may exhibit a T g the same as or very slightly higher than that of the matrix …”

Hydrophobic modification of ZnO nanostructures surface using silane coupling agent

“…Moreover, the acidic or alkaline condition could accelerate the reaction. Such specific methoxyl hydrolyzation and condensation mechanism were also used by other researchers .…”