Mechanical properties of polymer/liquid crystal systems prepared by electron-beam and ultra-violet processing: Filling effect and plasticization

Mechanical properties of Electron Beam and Ultra-violet cured Poly (tripropyleneglycoldiacrylate) (Poly-TPGDA)/liquid crystal (LC) systems were investigated. The presence of low molecular weight LC molecules in the polymer matrix modifies dramatically the dynamic and static mechanical behavior of the obtained composite materials. Above the glass transition temperature Tg (LC), dilution of the initial mixture with a low molecular weight LC like E7 leads to a significant weakening of the film mechanical strength. At temperatures below Tg (LC) a strong temperature dependence on the storage tensile modulus was found for EB-cured networks, including 30-50 wt.-% LC, the LC reinforces the polymer by an increase of the storage tensile modulus. In the case of the UV-cured TPGDA/LC system, the plasticizing effect of the LC remains dominant from −100 to +100 ∘C.