Intrinsic viscosity–molecular weight relationship and hydrodynamic volume for pullulan
Intrinsic viscosity–molecular weight relationship and hydrodynamic volume for pullulan
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DOI：
10.1002/app.22324
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发表时间：
2006-06
影响因子：
3
通讯作者：
M. Kasaai
中科院分区：
文献类型：
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作者：
M. Kasaai
确定标记 - houwink-sakurada（MHS）方程a和k的数值方法，对两个具有狭窄和宽分子量分布（MWD）的plullulan标准样品的成功进行了测试，并考虑了其多分散性比较了影响固有的粘度和粘度常数A和K（在Pullulan的文献中发表）。讨论了该研究的过程，以确定pullulan的水动力体积的正确值。 [η] = 1.990×10 -4 m V 0.667 = 1.990×10 -4 Q MHS M W 0.667 = 1.956×10 -4 m W 0.667（窄MWD）[窄MWD）= 2.263×10 -4 m V 0.657 = 2.263×10 -4 Q MHS M W 0.657 = 2.056×10 -4 m W 0.657（宽MWD），其中Q MHS是多分散性校正因子，并且[如果]是dl g -1中的内在粘度。 K与指数A是线性的，并且该曲线用于估计带有已知指数A的Pullulan的常数K。解决方案。
A numerical method for determination of Mark-Houwink-Sakurada (MHS) equation constants, a and K, was tested with success for two series of pullulan standard samples having narrow and broad molecular weight distributions (MWD) and taken into account their polydispersity. Different solvents, which were used to determine the intrinsic viscosities and the viscometric constants, a and K (published in the literature for pullulan), were compared. The various parameters affecting the constants are discussed. The procedure to determine the correct value of the hydrodynamic volume for pullulan was also described. This study resulted in the following MHS equations for narrow and broad MWD series of pullulan samples with M w in the range of 5-1000 kDa: [η]=1.990×10 -4 M v 0.667 =1.990×10 -4 q MHS M w 0.667 =1.956×10 -4 M w 0.667 (Narrow MWD) [η] = 2.263×10 -4 M v 0.657 =2.263×10 -4 q MHS M w 0.657 =2.056×10 -4 M w 0.657 (Broad MWD) where q MHS is the polydispersity correction factor and [if] is the intrinsic viscosity in dL g -1 . The plot of log K versus exponent a was linear and inversely related. This curve was used to estimate the constant K for pullulan with a known exponent a. Among various reported solvents, the diluted aqueous salt solutions have more advantages than other solvents.