Nitromethane liquid temperature range

Rohrschneider and McReynold extended the RI system to predict a PI for various stationary phases measured at a column temperature of 120°C with a 20% (w/w) loading, to minimise retention contributions from the diatomite support [11,12]. A set of five reference compounds were selected to reflect a range of polar characteristics and functional groups benzene, X butanol, Y 2-pentanone, Z nitromethane, [/ and pyridine, S. Squalane, 2, 6, 10, 15, 19, 23-hexamethyltetracosane (C30H62), is used as the reference stationary phase as it is a readily available completely non-polar, non-volatile liquid, bp = 176 at 0.05 mm. The values of X, Y, Z, U and S represent the relative affinities of the reference compounds for the stationary phase, calculated as the differences, ARI, between the RI of the reference on a chosen stationary phase compared to the RI on squalane. The polarity index, PI, is the mean of the RI values (Table 5.2). 

Crystallization of cellulose acetates (d.s. 2.2—3.0) has been achieved by annealation in the presence of either nitromethane or nitromethane-n-butanol in overcooled dilute solutions. Cellulose acetate I crystallized over the whole range of compositions when annealed above the glass temperature thermal treatment of cellulose acetate II brought about crystallization of samples of d.s. 2.6, whereas heating in the presence of polar liquids resulted in crystallization over the whole range of compositions. Cellulose acetate I was converted into cellulose acetate II on heating in ethanol, and cellulose acetate II crystallized spontaneously from acetone at room temperature. A comparison of the crystalline forms obtained from cellulose acetates of different d.s. was also made. 

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