A STATIC AND DYNAMIC STUDY OF THE MECHANICAL PROPERTIES OF ELECTRON BEAM CURED PDLC FILMS

摘要

This paper reports a study of 'static and dynamic mechanical properties of electron beam (EB) cured polymer dispersed liquid crystals. These systems consist of micron-sized, droplets dispersed, in a solid polymer matrix. They are prepared according to the polymerization induced phase separation process initiated by exposure to electron radiation. A difunctional monomer Tripropy-lene Glycol Diacrylate in short TPGDA is used with the eulectic liquid crystal mixture E7 having a nemalic to isotropic transition temperature at 60°C. Strong effects are found on Young modulus and rubbery state modulus in terms of the EB dose and the liquid crystal concentration. As the concentration of small molecules increases, these mechanical parameters drop significantly together with the glass transition temperature Tg of the polymer showing a plasticizing effect. The results for Tg are confirmed by DSC thermograms in terms of liquid crystal concentration and EB dose.