Temporary network formation of hyaluronate under a physiological condition. 1. Molecular-weight dependence
✍ Scribed by Toshio Yanaki; Toshijiro Yamaguchi
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 614 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
SYNOPSIS
T h e dynamic shear moduli at various frequencies and stress growth after the sudden start of steady shear were measured for 1% HA (hyaluronic acid) solutions with different molecular weights. From the results of the zero shear viscosity, qo, the steady shear compliance, Jx, and A7 defined as A ~J = vovs (cc ) , where va (cc ) is the apparent viscosity a t the steady state, it was shown that the molecular mechanism of flow of 1% HA solutions was classified into four regions with respect to molecular weight: ( I ) the viscosity-average molecular weight M , < 35 X lo4, HA chains are dispersed molecularly in solution; (11) 35 X lo4 < M , < 100 X lo4, the polymer chains form a weak entanglement network observed only through p o ; (111) 100 X lo4 < M , < 160 X lo4, the network is strengthened with increasing molecular weight and becomes detectable through both qo and &! and also through the overshoot phenomenon; and (IV) 160 X lo4 < M y , the network is "saturated" or "completed" dynamically. This is the conjecture presented for the first time by the present work.