RHEOLOGY OF HYDROXYPROPYLCELLULOSE SOLUTIONS
RHEOLOGY OF HYDROXYPROPYLCELLULOSE SOLUTIONS
复制标题
DOI：
10.1002/polb.1986.180240118
复制
发表时间：
1986-01-01
影响因子：
--
通讯作者：
HAUDIN, JM
中科院分区：
文献类型：
--
作者：
NAVARD, P;HAUDIN, JM
使用锥板流变仪和毛细管流变仪研究了羟丙基纤维素（HPC）-乙酸溶液的流变性，聚合物浓度范围为10 - 80%。各向同性溶液在较高剪切速率下表现出牛顿平台，随后是假塑性区。当浓度C <27%时，表观粘度变化为C5.2;当浓度C<30%时，表观粘度变化为C13。在30%和35%之间存在双相间隔（各向同性和双相）。在C = 30%时观察到粘度的最大值，粘度峰的高度是剪切速率的递减函数。各向异性解是强粘弹的。各向同性和各向异性解都给出了结果（表观粘度、第一法向应力差、松弛时间等）。这与土井的理论并不一致。这是可以理解的，因为HPC链不能用刚性杆来建模。在加热时，各向异性HPC-乙酸溶液经历各向异性到各向同性的相变，这很容易通过第一法向应力差和表观粘度的温度依赖性的最大值来检测。
The rheology of hydroxypropylcellulose (HPC)—acetic acid solutions was investigated by using a cone‐and‐plate rheometer and a capillary rheometer, for polymer concentrations ranging from 10 to 80%. Isotropic solutions exhibit a Newtonian plateau followed at higher shear rates by a pseudoplastic zone. The apparent viscosity varies asC5.2if concentrationCis less than 27% and asC13for 27% <C< 30%. A biphasic interval (isotropic and cholesteric phases) exists between 30 and 35%. A maximum in viscosity is observed atC= 30%, the height of the viscosity peak being a decreasing function of shear rate. Anisotropic solutions are strongly viscoelastic. Both isotropic and anisotropic solutions give results (apparent viscosity, first normal‐stress difference, relaxation time, etc.) which are not in good agreement with Doi's theory. This is understandable since the HPC chain cannot be modeled by a rigid rod. Upon heating, anisotropic HPC—acetic acid solutions undergo an anisotropic to isotropic phase transition which is easily detected by a maximum in the temperature dependence of the first normal‐stress difference and of the apparent viscosity.