Relation between intrinsic viscosity and polymerization degree of PET

By the correct calculation of PET intrinsic viscosity to determine the polymerization degree is the key point in the control of proper production of high quality PET. The different solvent systems for measuring the relative viscosity of PET and the calculation method of intrinsic viscosity used in the domestic plants are enumerated. The calculation method of calculating PET polymerization degree with its intrinsic viscosity was emphatically explained by introduction the relation formula between intrinsic viscosity and molecular mass of the phenol and tetrachloroethane solvent system (mixing ratio 3/2 by mass).