Cannon-Ubbelhode

Molecular characterization of the polymers consisted of intrinsic viscosity measurements and size exclusion chromatography. The intrinsic viscosities were measured in a solvent mixture of phenol and o-dichlorobenzene using Cannon-Ubbelhode viscometers. Polyethylene terephthalate equivalent molecular weights were determined using a Waters 244 GPC in a solvent mixture of methylene chloride and hexafluoroisopropanol. The results from NMR, DSC, and molecular characterization are summarized in Table I. Techniques for the dynamic x-ray diffraction studies are described elsewhere (2). 

Viscosities were measured with a Cannon-Ubbelhode viscometer at 30.0°C in a bath regulated to within 0.01 °C. 

For both GPC/LALLS and intrinsic viscosity measurements, Burdick Jackson distilled-in-glass, UV grade tetrahydrofuran (THF) was used. GPC/LALLS e q>eriments were conducted at a constant, pulse-free solvent flow-rate of 1-0 ml/min. Solute concentrations were 0.1% (w/vol.) and the volume of injected solution ranged from 0.3 ml to 0.5 ml. Intrinsic viscosities for CTC in THF were measured at 25 C in a Cannon-Ubbelhode four-bulb shear dilution capillary viscometer (Size 50). Kinetic energy corrections were negligible eind the data were corrected for sheeu effects by extrapolation of n /c to zero shear rate (10). 

Inherent viscosities (I.V.) of the polymers were measured using a 50 bore Cannon-Ubbelhode dilution viscometer immersed in a thermostatically controlled water bath at 25 C at a concentration of 0.025 gms/25 ml. 

The viscosity measurements were performed at 135°C by a Cannon-Ubbelhode viscosimeter. Concentrations of 100 mg/10 mL in tetrahydronaphtalene were used. 

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