The effect of blending polymers of different molecular weight on the Q value (⁠Q=Mw/Mn) of the blend has been considered. A mathematical expression is derived, and it shows by a simple application to monodisperse systems that blending over a wide molecular weight range is necessary to give high Q values. These principles are then applied to the ease of Ziegler and Phillips type high density polyethylenes having wide log-normal molecular weight distributions. In this way it is shown that only blending over a very wide melt index range, e.g., 1000/1, can be expected to have a measurable effect on Q. A series of physical measurements on blended and homogenized Ziegler polyethylenes shows no significant differences between blends and directly produced polymers.

This content is only available as a PDF.
You do not currently have access to this content.