DETERMINATION OF THE MARK-HOUWINK EQUATION PARAMETERS AND THEIR INTERRELATIONSHIP

This paper presents a trial and error method for determining the optim al values of k and a of the Mark-Houwink equation using polymers with different intrinsic viscosities ([eta]) and molecular weight distribut ion (MWD);Is standards. The values of k and a for polystyrene, EP-copo lymer, polypropylene, polyethylene, polyvinylchloride, and polycarbona te, etc., have been determined with this method. The relative errors o f the resultant [eta] are below 6%, 4% or 3%. The viscosity-average mo lecular weight (M,) of polystyrene standards agrees well with those of Pressure Chemical Co.; the weight- and number-average molecular weigh ts of EP-copolymer coincide with that measured by using the low angle laser light scattering KMX-6 and the Knauer membrane osmometer, respec tively. Thus, the method possesses high precision and can be applied t o polymers with a wide range of molecular weight (MW) and molecular we ight distribution (MWD).