Plant Polymer Research Unit, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N, University Street, Peoria, IL 61604, USA.
Functional Foods Research Unit, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N, University Street, Peoria, IL 61604, USA.
Carbohydr Polym. 2017 Apr 1;161:140-148. doi: 10.1016/j.carbpol.2017.01.011. Epub 2017 Jan 5.
The rheological properties of aqueous solutions and films made from blends of polyvinyl alcohol (PVOH) and amylose-hexadecylammonium chloride inclusion complexes (Hex-Am) were investigated to better understand the polymer interactions and processing parameters. Aqueous solutions of Hex-Am displayed non-Newtonian shear thinning characteristics, becoming highly viscous at 4.2% solids and forming a strong mechanical gel at 10% solids. Cationic Hex-Am was observed to have dramatically different rheological temperature response profiles from anionic amylose-sodium palmitate inclusion complexes, displaying a precipitous increase in viscosity upon cooling from 95°C to 50°C. Aqueous solution blends of 1:1 PVOH/Hex-Am lack this precipitous increase in viscosity, indicating that PVOH reduces amylose-chain entanglement. Films cast from varying blends of Hex-Am and PVOH were thermostable to 200°C, and displayed decreasing storage modulus with increasing concentrations of PVOH in film blends. Films cast from Hex-Am/PVOH absorb water vapor at lower rates than their constitutive polymers.
研究了聚乙烯醇（PVOH）和直链淀粉-十六烷基氯化铵包合物（Hex-Am）共混物的水溶液和薄膜的流变性能，以更好地了解聚合物相互作用和加工参数。Hex-Am 的水溶液表现出非牛顿剪切变稀特性，在 4.2%固含量时变得非常粘稠，并在 10%固含量时形成强机械凝胶。与阴离子直链淀粉-硬脂酸钠包合物相比，阳离子 Hex-Am 的流变温度响应曲线有显著差异，在 95°C 冷却至 50°C 时，其粘度急剧增加。1:1 PVOH/Hex-Am 的水溶液混合物没有这种粘度急剧增加的现象，这表明 PVOH 减少了直链淀粉链的缠结。由不同比例的 Hex-Am 和 PVOH 共混物浇铸的薄膜在 200°C 下热稳定，并且随着薄膜混合物中 PVOH 浓度的增加，存储模量降低。与组成聚合物相比，由 Hex-Am/PVOH 制成的薄膜吸收水蒸气的速度较慢。
