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In order to develop a method for preparation of aromatic polyesters called polyarylates (PARs) with highly thermal resistance, transparent and noncrystalline propatics, and highly thermal fluidity, we examined the polymerization of bisphenol (A, B or C) and iso- and/or tere-phthaloyl chlorides using tetrabutylammonium bromide as a phase-transfer catalyst and benzoyl chloride as an end-capping reagent at room temperature. The obtained PARs were cast and subjected to the differential scanning calorimetry (DSC), melt flow rate (MFR), and X-ray diffraction (XRD) analyses. It was found that their solubilities, noncrystallinifies, and Tg were largely dependent on the structure (A, B or C) of the reactant bisphenol and the iso- and tere-ratio of incorporated phthaloyl groups; the noncrystallinity and high thermal fluidity were induced more effectively with reduced symnmetry of the bisphenol ester unit. The observed scattering intensity of the XRD reflection patterns of PARs revealed that the PARs were transparent and noncrystalline to the same extent as a commercially available transparent resin, PMMA. Thus, a transparent and noncrystalline PAR resin and its synthetic method are both in hand. [ABSTRACT FROM AUTHOR]

Commercial optical resins on their moldings have been required to be dried in their water contents, 0.01˜0.05 wt%, in hot airflow. However, the structure of wet resins and the location and role of water molecules in them remain unknown. Polymerization of Bisphenol A and iso- and terephthaloyl chlorides by the interfacial polycondensation method provides a polyester, PARFree, which has phenolic OH groups at the polymer ends. In contrast, the polymerization in the presence of benzoyl chloride, BC, causes benzoylation of the end OH groups to give fully esterified polyesters, PAREC. This method gave us a new technology for production of colorless, transparent and heat resistant optical fibers. We found that when PAR films using dichloromethane were cast on a glass dish, the glass surfaces often are widely exfoliated with the resin film. In this study, this surface-exfoliation phenomenon is explored. [ABSTRACT FROM AUTHOR]

Thermal resistant and transparent aromatic polyesters (PARs) were prepared in order to manufacture new plastic optical fibres (POF) of step-index types. The PARs were successfully obtained by using bisphenol A, iso- and tere-phthaloyl chlorides via an interracial polycondensation (IPC) in the presence ofbenzoyl chloride not only as a molecular weight controller but also as an end-capping (EC) reagent for protection of the end-OH groups of the PAR molecules, together with a tetra-n-butylammonium bromide as catalyst. The resultant end-capped PAR (PAREC) increased their melt flow rates with increasing the degree of the benzoylation, and did not show a pale yellow color; this absence suggests the generation of phenoxy radicals in the POFs manufactured at temperatures higher than 260°C. The PAREC POFs may be used as local area network cables in vehicles and aircraft because of fairly low attenuation values. [ABSTRACT FROM AUTHOR]