NOVEL PDLC TYPE DISPLAY BASED ON CELLULOSE DERIVATIVES

A novel type of PDLC display utilizing solid films obtained from the c ellulose derivative hydroxypropylcellulose (HPC) with molecular weight s of 60000 (HPC60000) and 100000 (HPC100000), cross-linked with two di fferent di-isocyanates, 1,4-di-isocyanatobutane (BDI) and 1,6-di-isocy anatohexane (HDI), is presented. This kind of display (optical cell) i s composed of a porous elastomeric film (20-60 mu m thick) of HPC-BDI or HPC-HDI, impregnated with a nematic liquid crystal and contained be tween two transparent conducting substrates. The electro-optic behavio ur of several optical cells is studied as a function of film thickness , the molecular weight of the polymer and the cross-linking agent. The preliminary studies presented in this work show that these systems pr esent good contrast, high transmissivity in the on state and switching times in the range of some milliseconds to hundreds of milliseconds.