DETERMINATION OF MOLECULAR-WEIGHT DISTRIBUTION OF CELLULOSE BY CONVERSION INTO TRICARBANILATE AND FRACTIONATION
DETERMINATION OF MOLECULAR-WEIGHT DISTRIBUTION OF CELLULOSE BY CONVERSION INTO TRICARBANILATE AND FRACTIONATION
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DOI：
10.1002/pol.1976.170140202
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发表时间：
1976-01-01
影响因子：
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通讯作者：
BOHACKOVA, V
中科院分区：
文献类型：
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作者：
DANHELKA, J;KOSSLER, I;BOHACKOVA, V
将两种纤维素样品（分子量为2.97 × 105和1.25 × 105）转化为氨基甲酸酯（CTC），然后通过洗脱方法在丙酮-水洗脱混合物的恒定组成下进行分馏，柱温从−30°C逐渐升高至30°C，并通过GPC方法在丙酮和四氢呋喃中进行分馏。四氢呋喃似乎是更合适的溶剂。通过四氢呋喃中的光散射法测定通过洗脱分级获得的级分的分子量。通过GPC方法测定级分的宽度（平均Mw/Mn= 1.37）;测定四氢呋喃在25°C下的[η]值和Mark-Houwink常数（K= 5.3 × 10 - 3，a= 0.84）。通过由此获得的级分构建GP方法的校准曲线;证明也可以使用根据Benoit的通用校准曲线。已经证明，纤维素的分子量分布可以通过转化成CTC，然后通过洗脱分级分离（用于制备目的）或通过GPC方法分级分离（用于分析目的）来方便地测定。
Two samples of cellulose (molecular weight 2.97 × 105and 1.25 × 105) were transformed into carbanilates (CTC) which were then fractionated by the elution method at a constant composition of the acetone‐water elution mixture with the column temperature gradually increasing from −30°C to 30°C, and by the GPC method in acetone and tetrahydrofuran. Tetrahydrofuran appeared to be a more suitable solvent. The molecular weights of fractions obtained by the elution fractionation were determined by the light‐scattering method in tetrahydrofuran. The width of fractions was determined by the GPC method (averageMw/Mn= 1.37); the [η] values and the Mark‐Houwink constants (K= 5.3 × 10‐3,a= 0.84) for tetrahydrofuran at 25°C were determined. The calibration curve for the GP method was constructed by means of the fractions thus obtained; it was demonstrated that the universal calibration curve according to Benoit can also be used. It was demonstrated that the molecular weight distribution of cellulose can be conveniently determined by conversion into CTC followed either by the elution fractionation (for preparative purposes) or by fractionation by the GPC method (for analytical purposes).