Determinations of Molecular Weight of Lignin Degradation Products by Three Methods
Determinations of Molecular Weight of Lignin Degradation Products by Three Methods
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三种方法测定木质素降解产物的分子量
DOI：
10.1021/ac60136a020
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发表时间：
1958
影响因子：
7.4
通讯作者：
C. Schuerch
中科院分区：
文献类型：
--
作者：
S. Gross;K. Sarkanen;C. Schuerch
用冰点下降法和等压法分别测定了乙醇、水和硫酸盐木质素在二氧六环和碳酸乙烯酯中的分子量和在四氢呋喃中的分子量。已使用特殊技术来消除由于灰分含量和吸附溶剂而引起的误差。二氧六环中分子量的浓度依赖性表明存在过度缔合。在这项工作中，在四氢呋喃中观察到的不稳定结果以及以前的工作人员在其他溶剂中观察到的不稳定结果可能也是由于缔合。在碳酸乙烯酯中进行冰点测定是这三种方法中最方便的方法。在此溶剂中木质素的分子量是最可重复的。用这种方法，缔合作用显然不是问题，因为这些值实际上与浓度无关，而且小于用其他方法得到的值。指出了该方法在其它复杂产品中的应用。
Molecular weight determinations on ethanol, hydrol, and kraft lignins have been made in dioxane and ethylene carbonate by cryoscopy and in tetra-hydrofuran by an isopiestic method. Special techniques have been used to eliminate errors due to ash content and adsorbed solvents. The concen-tration dependence of molecular weights in dioxane indicatesexcessive association. Erratic results observed in tetrahydrofuran in this work and in other solvents by previous workers are probably also due to association. Cryoscopy in ethylene carbonate is the most convenient method of the three. Molecular weights of lignins in thissolvent are most reproducible. Association is apparently not a prob-lem with this method, for the values are practically concentration independent and are less than by other methods. Its application to other complex products is indicated.