Structure-property relationships for poly(dimethylsiloxane) networks in-situ filled using titanium 2-ethylhexoxide and zirconium N-butoxide

摘要

For the past decade or so, an alternative to the energy demanding ex-situ filling of elastomers had been in-situ filling. The in-situ technique is a solvent-free synthesis at room temperature that can be used to produce in a continuous process significant quantities of colloidal-size particles. These particles can be produced from various alkoxides using either base or acid catalysts. There are many advantages to this in-situ process, for example particle sizes and distributions can be controlled by reaction conditions, low temperatures are involved, and solvent is unnecessary. SAXS (small angle X-ray scattering) is one of the important tools used to characterize such filler particles, with respect to their different shapes and sizes. Using Porod's law and Guinier's law it is possible from the SAXS data to obtain the Rg (radius of gyration), and the slope of the Porod regime, which gives an indication of the shape of the particle. In this study an effort has been made to synthesize in-situ zirconia and titania particles in poly(dimethyl- siloxane) (PDMS) networks. Zirconium n-butoxide and titanium 2-ethylhexoxide (TEH) were used in this study to generate the particles. The advantages of using TEH are that it has a longer chain and a side group, ethyl, which will reduce the speed at which these particles are formed (compared to those in an earlier study with titanium n-propoxide).