VISCOSITY MOLECULAR-WEIGHT RELATIONSHIPS FOR POLY(ETHYLENE-TEREPHTHALATE) IN HEXAFLUOROISOPROPANOL PENTAFLUOROPHENOL USING SEC LALLS

In the reported experiments, viscosity-molecular weight characterization of poly(ethylene terephthalate) (PET) in hexafluoroisopropanol (HFIP), pentafluorophenol (PFP), and HFIP/PFP has been made by using size exclusion chromatography-low angle laser light scattering (SEC-LALLS) measurements. By combining molecular weight information, obtained without the need of any SEC calibration curves, with intrinsic viscosity measurements, on several broad molecular weight PET samples, the Mark-Houwink coefficients for the five PET-solvent systems have been determined. The coefficients correspond to those which would be obtained by using a large number of relatively monodisperse samples of PET covering a molecular weight range of about 2 multiplied by 10**3 to 2 multiplied by 10**5. Data is also provided which shows that intrinsic viscosities for PET in HFIP, PFP, HFIP/PFP, OCP, and PTCE can be determined from a single viscosity measurement at a finite concentration. Data for interconverting intrinsic viscosities determined in any of these five solvents is also given.