Rheological Properties of Deacetylated Xanthan in Aqueous Media
Rheological Properties of Deacetylated Xanthan in Aqueous Media
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DOI：
10.1271/bbb1961.48.2987
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发表时间：
1984-12
期刊：
影响因子：
--
通讯作者：
M. Tako;Sanehisa Nakamura
中科院分区：
文献类型：
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作者：
M. Tako;Sanehisa Nakamura
脱乙酰黄原胶水溶液的流动性在浓度低于0.1%时接近假塑性，而在浓度高于0.3%时接近塑性。在不同浓度下，脱乙酰黄原胶的幂律流动指数略有不同。脱乙酰黄原胶的表观粘度在较低浓度（0.1 ~ 0.5%）时随温度的升高而降低，但随温度的升高而升高，在40°C时达到最大值，在1.0%时逐渐降低。与天然黄原胶相比，脱乙酰基材料在高浓度下表现出更高的动态粘弹性。在不同浓度下，脱乙酰黄原胶的动态粘弹性随温度的升高而降低。加入尿素（4.0 M）可降低脱乙酰黄原胶的动态粘弹性，这表明连接在侧链内部甘露糖残基上的乙酸残基有助于分子内缔合，从而降低了黄原胶的动态粘弹性。
Flow properties of aqueous deacetylated xanthan solutions could be approximated to pseudoplastic behavior at concentrations below 0.1% but to plastic behavior above 0.3%. The flow indices in the power law for the deacetylated xanthan were somewhat different at various concentrations. The apparent viscosity of deacetylated xanthan decreased with increasing temperature at relatively low concentrations from 0.1 to 0.5%, however, it increased with increasing temperature, showed a maximum value at 40°C and decreased gradually at 1.0%. Compared with native xanthan, deacetylated material showed higher dynamic viscoelasticity at high concentrations. The dynamic viscoelasticity of deacetylated xanthan decreased with increasing temperature at various concentrations. The dynamic viscoelasticity of deacetylated xanthan was decreased by addition of urea (4.0 M).This suggests that acetate residues, which are attached to the inner mannose residues of the side chains, contribute to the intramolecular association, and tha...