Understanding Amylose Crystallinity in Starch-Clay Nanocomposites
Understanding Amylose Crystallinity in Starch-Clay Nanocomposites
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DOI：
10.1002/polb.21437
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发表时间：
2008-05
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影响因子：
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通讯作者：
D. Chaudhary
中科院分区：
文献类型：
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作者：
D. Chaudhary
直链淀粉-水相互作用是淀粉基质内重要平衡过程的一部分，导致直链淀粉链缓慢重结晶和淀粉基质中各向异性特性的增长。本文重点介绍了纳米粘土对 (a) 直链淀粉结晶度的结构发展和 (b) 淀粉基质失水率的影响。通过改变纳米复合材料的含量（1.5-4 wt%），获得了一种独特的微观结构，可以“锁定”水分，并且发现，在淀粉基质的每单位重量基础上，添加 4 wt% 的纳米粘土会导致基质中额外含有 8.5% 的水。此外，还发现，将纳米粘土的重量从 2% 增加到 4%，复合材料模量跃升 100%，表明粘土纳米复合材料和淀粉聚合物之间具有优异的相互作用。对淀粉结晶度数据的分析表明，纳米复合材料阻碍了淀粉分子（特别是长链直链淀粉成分）的流动性，从而限制了淀粉周围“相关”水的运动，这使“锁定”水增加了~10%。结果强烈表明，直链淀粉-水-粘土相互作用可能形成新的结构单元，从而增强复合材料的性能。 © 2008 Wiley periodicals, Inc. J Polym Sci B 部分：Polym Phys 46：979–987，2008
The amylose–water interaction is part of an important equilibrating process within the starch matrix leading to slow recrystallization of amylose chains and growth of anisotropic properties in the starch matrix. This article highlights the influence of nanoclay on (a) the structural development of amylose crystallinity and (b) the rate of water loss from the starch matrix. By varying the nanocomposites level (1.5–4 wt %), a unique microstructure is obtained that “locks” moisture and it was found that on a per unit weight basis of the starch matrix, addition of 4 wt % nanoclay resulted in additional 8.5% water in the matrix. Also, it was found that increasing the nanoclay from 2 to 4% by weight, the composite modulus jumped by 100% indicating excellent interaction between clay nanocomposites and starch polymer. Analysis of the starch crystallinity data indicates that nanocomposites retard the mobility of the starch molecules (specially the long chain amylose component) to restrict the movement of “associated” water around starch and this increases the “locked” water by ∼10%. The results strongly suggest that a new structural unit may be formed by amylose–water–clay interaction which enhances the composites properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 979–987, 2008