서강대학교

초록/요약

Materials for optical film were used as various forms such as transparent sheets, films and coating, which have desirable special functions through the precision process. Also, they take special roles of products in simplicity, abrasion ability, gas barrier ability and flexibility. Being superior to simple common plastics, these optical materials have outstanding functions of a polarization, an improvement of color purity, an anti-reflection, an anti-static, an interception of infrared ray and an protection of layer. Therefore, the development of new functional products is faced with the one of innovative display products. It could be explained that the success of flat panel display depends on transparent plastic materials. Major transparent plastic materials are polycarbonate(PC), polyethyleneterephthalate(PET), polymethylmethacrylate(PMMA), polyethersulfone(PES), polyvinylalcohol(PVA), triacetylcellulose(TAC), polyethylene(PE), polyimide(PI), cylic olefin copolymer(COC) and so on, which is used it via the proper sophisticated process rather than used itself. Nowadays Japanese companies cover these markets in the whole world. Especially, they monopolized completely these markets with LCD polarizers and compensation films made from PVA, PC, PO and TAC. To overcome an adverse balance of trade, it is important to develop the process of TAC film regrading the national matter. In this study, optical TAC films were fabricated by the solvent casting method using TAC flakes synthesized by acetylation of cellulose. The degree of acetylation was about 62%. Their properties were observed according to molecular weight. We found that their physical and optical properties became clear above 250,000 MW. To improve their brittleness, plasticizers(TPP, BDP) were used. Their anisotropy coming from MD/TD direction was observed according to an amount of plasticizer and draw ratio. And, how temperature affects the crystallinity of TAC film also was observed because of that depending on drying process. The structure of TAC flakes was analyzed by nuclear magnetic resonance(NMR) and wide angle x-ray scattering(WAXS), and their mechancal and physical properties were measured by differential scanning calorimetry(DSC), thermal gravity analysis(TGA), thermomechanical analysis(TMA), dynamic mechanical analysis(DMA) and universal testing machine(UTM). Their optical properties were also characterized by UV-Visible spectroscopy and Retardation(Re,Rth). The results showed that their physical and optical properties could be modulated according to the proper process condition such as molecular weights, an amount of plascticizers, thermal treatments , draw ratio.