聚乙烯醇-硼酸鈉錯離子稀釋及半稀釋水溶液之動態光散射及黏彈性研究

Dynamic Light Scattering and Viscoelasticity from Dilute and Semidilute Poly(vinyl alcohol)-Borax Complex Aqueous Solution

劉遠鋒(Yuan-Feng Liu)

指導教授 ： 林秀麗 ； 余子隆

元智大學/工程學院/化學工程與材料科學學系/碩士(2002年)

摘要

無資料

關鍵字

聚乙烯醇 ； 硼酸鈉 ； 動態光散射 ； 黏彈性

並列摘要

In this study, we report solution and weak gel behavior of poly(vinyl alcohol) (PVA)-borax complex in aqueous solution by laser light scattering and rheometer. The experimental concentration is [PVA]=2~60 g/L, [borax]=0.0 M, 0.1 M and 0.2 M. The experiments were carried out at 25℃ and at scattering angles ranged from 30°to 120°. The frequency rang in rheometry study is from 10^-1 to 10^2 1/sec. The dynamic light scattering (DLS) data show that PVA molecules have two relaxation modes when no borax is present in aqueous solution. It is found that the amplitude of slow mode increases with PVA concentration. When PVA aqueous solutions are mixed with 0.2 M borax, the DLS data show that PVA-borax aqueous solution is solution state, while PVA concentration is lower than 20 g/L. But as PVA concentration is higher than 40 g/L, PVA/borax water system is in gel state. The dynamic rheometer data show that all the PVA-borax aqueous solutions are solution state, even PVA concentration is higher than 40 g/L with borax concentration of 0.2 M. The dynamic rheometric data reveals that PVA/borax water system behaves like a solution. We suggest that PVA/borax water system is a physical weak gel. Crosslink points which are formed by diols and borate ions in equilibrium state are ionic bonds. Crosslink points have a finite life time (τlife).

並列關鍵字

poly(vinyl alcohol) ； borax ； dynamic light scattering ； viscoelasticity

參考文獻

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