Viscoelastic properties of polymer solutions in simple shear flow

VISCOELASTIC PROPERTIES OF POLYMER SOLUTIONS IN SIMPLE SHEAR FLOW 

Viscoelastic properties of polymer solutions may be of practical importance, e.g. in the flow of these solutions through technical equipment. For concentrated polymer solutions the viscoelastic properties show great analogy with those of polymer melts. For dilute solutions (c ccr) the analogy decreases with decreasing concentration. 

For sufficiently low to the curves for log G and log G plotted vs. log to are straight lines with slopes 2 and 1, respectively. For sufficiently high frequencies 

So that G (co) and G (to)-toris coincide at high frequencies and the slopes of the straight lines are Vi in the above mentioned plot and tan 5 = tan(1/27m) = tan(rc/4) = 1, where n is the slope at high frequencies. 

In Zimm s model the expression for the relaxation times is more complex the relaxation times ti are proportional to p 3/z in the non-draining case instead of to p 2 in the free-draining case and S z = 2.369. This leads to slopes of 2 and 1 at sufficiently low frequencies, whereas for sufficiently high frequencies 

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