Mechanically controlled, morphologically determined sol–gel derived UV curable hybrid nanocomposites: SAXS and DMTA studies
- 288 Downloads
This work reports preparation of organic–inorganic hybrid materials by sol–gel method. To this end, UV cured urethane acrylate and different functional monomers were used as organic network together with tetraethyl orthosilicate (TEOS) as inorganic network former and 3-methacryloxy propyltrimethoxy silane (MEMO) as network modifier. The effect of sol–gel precursor’s ratio on morphological properties of hybrid network was studied by small angle X-ray scattering (SAXS). Dynamic mechanical thermal analysis (DMTA) was performed to investigate the mechanical behavior of hybrid films. Whilst hybrids with low content of TEOS and high amounts of MEMO represented a “structural defect”, it was found that by increasing TEOS/MEMO ratio, the silica domain size decreased, showing a mass fractal behavior. This was attributed to a more compact structure of silica and a stronger hybrid network. The changes observed in compactness of hybrid films directly affected the glass transition temperature. By increasing the inorganic phase, more restriction in segmental motion of the polymeric phase occurred. Upon increasing TEOS/MEMO ratio a broader tan δ peak deduced from DMTA graphs was observed, indicating greater phase separation and higher heterogeneity.
KeywordsSol–gel Hybrids UV cured SAXS DMTA Nanocomposite
- 3.Iler RK (1979) The chemistry of silica. Wiley, New YorkGoogle Scholar
- 4.Brinker CJ, Scherer GW (1990) Sol–gel science: the physics and chemistry of sol–gel processing. Academic Press, New YorkGoogle Scholar
- 7.Andrianov KA (1955) Organic silicon compounds, State Science Publication House for Chemical Literature, MoscowGoogle Scholar
- 8.Vorankov MG, Mileshkevich VP, Yuzhelevski YA (1978) The siloxane bond. Consultants Bureau, New YorkGoogle Scholar