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Copolyesters were synthesized from bis(hydroxyethyl) naphthalate/bis-(hydroxymethylcyclohexane)naphthalate (BHEN/BHCN) with various compositions. Copolyesters having intrinsic viscosities of 0.58-0.65 dL g were obtained by melt polycondensation in the presence of metallic catalysts. The optimum condition for polyethylene-1,4-cyclohexanedimethylene naphthalate (PECN) copolyester manufacturing is the transesterification under a nitrogen atmosphere for 4 h at a temperature of 245 { 5ЊC followed by polymerization under 2 mmHg for 50 min at a temperature of 290-320ЊC. Most copolyesters have better thermal stability than has poly(ethylene naphthalate) (PEN) and the effect of the cyclohexane-dimethylene structure on the thermal and crystalline properties of the resulting copolyesters was investigated using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Glass transition temperatures of the copolyesters were in the range of 115.2-138.4ЊC, and 10% weight losses in nitrogen were all above 453ЊC. The solubility, crystallinity, and moisture absorption of the copolyesters were also investigated.

SynopsisMeasurements of thermal conductivity of heat-treated and 7-irradiated polytetrafluomethylene (FTFE) are reported for the 10-180"C. temperature range. Conductivity of PTFE is observed to be largely temperatureindependent with a value of about 6.5 X cal./cm.-sec.-"C. for the as-received material. Slight anomalous changes in conductivity data occur in the 20 and 125°C. temperature regions. The former is assumed to be associated with the ht-order crystalline transitions which occur near 19 and 30"C., while the latter may be associated with a relaxation process near 400°K. The anomaly in the conductivity which occurs near 20°C. is affected by annealing or radiation treatments, and is correlated with crystallinity and specific volume changes previously reported. The overall conductivity level is observed to decrease for annealed, quenched, or irradiated samples. From estimates of crystallinity, it is noted that the thermal conductivity is not a simple function of per cent crystallinity in these cases.

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Bis(hydroxyethyl)naphthalate (BHEN) was polymerized to polyethylenenaphthalate (PEN) in the presence of various metallic catalysts. The influence of the nature and concentration of these catalysts on the rate of polymerization has been investigated. The order of decreasing catalytic influence of various metal ions on the polymerization of BHEN was found to be: Ti > Sb > Zn > Co > Pb > Ni (Mg). The effect of the reaction temperature has also been studied. The optimal concentration of these catalysts and reaction temperature were found to be 30 x 10 .5 (mol/mol B HEN) and 285°-293 °C. Because of its insolubility in ordinary solvent, the molecular weight of PEN was measured using the light scattering method.