Yanaki T, Yamaguchi T
Shiseido Basic Research Laboratories, Nippacho, Yokohama, Japan.
Biopolymers. 1990;30(3-4):415-25. doi: 10.1002/bip.360300319.
The 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, eta 0, the steady shear compliance, J 0e, and delta eta defined as delta eta = eta 0 - eta a (infinity), where eta a (infinity) is the apparent viscosity at 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 Mv less than 35 X 10(4), HA chains are dispersed molecularly in solution; (II) 35 X 10(4) less than Mv less than 100 X 10(4), the polymer chains form a weak entanglement network observed only through eta 0; (III) 100 X 10(4) less than Mv less than 160 X 10(4), the network is strengthened with increasing molecular weight and becomes detectable through both eta 0 and J 0e and also through the overshoot phenomenon; and (IV) 160 X 10(4) less than Mv, the network is "saturated" or "completed" dynamically. This is the conjecture presented for the first time by the present work.
针对不同分子量的1%透明质酸（HA）溶液，测量了在不同频率下的动态剪切模量以及稳态剪切突然开始后的应力增长情况。根据零剪切粘度η0、稳态剪切柔量J0e以及定义为δη = η0 - ηa(∞)的δη（其中ηa(∞)是稳态下的表观粘度）的测量结果表明，就分子量而言，1% HA溶液的流动分子机制可分为四个区域：（I）粘均分子量Mv小于35×10⁴，HA链以分子形式分散在溶液中；（II）35×10⁴ ＜ Mv ＜ 100×10⁴，聚合物链形成仅通过η0观察到的弱缠结网络；（III）100×10⁴ ＜ Mv ＜ 160×10⁴，网络随着分子量的增加而增强，并且通过η0和J0e以及过冲现象均可检测到；（IV）Mv ＞ 160×10⁴，网络在动态上“饱和”或“完成”。这是本研究首次提出的推测。
