2730
NOTES
leads directly t~ the free and pure E-aminocaproic acid in a single step. The conversion after five days at 80" was about 20%, but the unreacted E caprolactam can be simply and quantitatively recovered, so that the actual yield is close to the theoretical. TJndoubtedly speedier and higher conversions can be obtained with higher temperatures arid pressures but this was not investigated.
Experimental e-Aminocaproic Acid.-Eleven and three-tenths grams (0.1 mole) of e-caprolactam2 was heated in an oven with 55 ml. of concentrated ammonia in a pressure-bottle for five days a t 80". The contents of the bottle were then evaporated to dryness, treated with 30 ml. of i-propanol, the precipitated e-aminocaproic acid filtered off, washed with i-propanol and dried: yield 2.6 g.; m. p. 201-202" (dec.). On distillation to dryness, the mother liquors yielded an oily residue which promptly crystallized; it had a m. p . of 65-68" and thus proved to be pure e-caprolactam. _ _ _ ~
Vol. 68
four molecules of ~ C ~ O H ~ ~ S O ~per N ~unit .H~O cell is 1.2G1 g./cc. From the size of the unit cell and the intensity distribution of thc diffraction effects, the structure of sodium 1-decanesulfonate hemihydrate seems identical with the other members of the hemihydrate series. UWVERSITY OF I~ASHINGTOY SEPTFVBER 23, 1 9 l t i SEATTLE 3, n ' A 5 H i Y G T O S RECEIYFI)
Electron Microscopic Structure of Cellulose Powder from Wood Pulp Ground in Very Dry Condition* BY 1'. H. HERMANS
In a previous paper' we have shown that on grinding of very dry cellulose fibers in a vibrating ball mill two characteristic types of disintegration product are observed, fibrillar ones still showing a crystalline nature on X-ray examination and an amorphous powder without clearly recognizable ( 2 ) s-Caprolactam was generously supplied by E. I. du Pant de structure. The former disappears more and Nemours & Co., Inc. more on prolonged grinding and the latter apparRESEARCH LABORATORY ently represents the final product, probably conGALATCHEMICAL DEVELOPMENT, Isc. sisting of crumpled or otherwise deformed fibrillar 61 SO. BROADW.4Y RECEIVED AUGUST30, 1946 elements admixed with porcelain powder from S . Y. YONKERS, mill abrasion. The electron micrograph reproduced in Fig. 5 of the paper cited showed powder X-Ray Crystallographic Data for Sodium from ramie fibers containing about 20% of porce1-Decanesulfonate Hemihydrate lain. Using balls of a harder ceramic material it was RY L. H:.JENSEN AND E. C. LINGAFELTER possible to reduce the ash content of the grinding X-Ray crystallographic data for the hemihy- products considerably. Powder from woodpulp drates of sodium 1-dodecane-, 1-tetradecane-, 1- fibers ground five hours and containing less than hexadecane- a.nd 1-octadecanesulfonate have been 3y0ash was used for the recrystallization experireported.' The hemihydrate of sodium l-dec- ments referred to in our previous paper. In the anesulfonate was now been obtained as extremely present note we shall briefly deal with a further small sitigle crystals suitable for X-ray diffraction electron microscopic study on the morphological studies. structure of this product in the original and in the Conditions for the growth of sodium l-dec- recrystallized state. anesulfonate hemihydrate differ from those for 9 s stated before, the particle size of the powder the hemihydrates previously reported. Sodium largely depends on the method of previous treat1-decanesulfonate hemihydrate crystallized from ment. In order to get the best possible dispersion a solution of approximate composition 15yo for examination with the electron microscope, a water, %yo 1,4-dioxane a t ca 5'. Work is in suspension of the powder in water was exposed to progress a t the present time to delineate the ultrasonic radiation (200,000 cycles). Particles temperature :and solvent conditions for the for- ranging between about 1-10 ,u were so obtained. mation of this and the other hydrates of the Figure 1 shows a typical particle of the original sodium 1-alkanesulfonates. powder so dispersed in water and then dried on I n addition to the habits observed for the other the collodion film. Figures 3 and 4 show typical hemihydrates, sodium 1-decanesulfonate hemi- particles of the same powder which had previously hydrate crystallizes as rhomb-shaped tablets, been heated in water a t 100' (recrystallized samextremely thin parallel to ( O O l ] and outlined by ple). There is no observable difference between (12 2). the original and the recrystallized preparations. X-Ray crystallographic data were obtained as Both consist of rather compact aggregates whose previously reported.' Cell constants for the actual structure is diiiicult to recognize. Since monoclinic unit cell are: a. = 6.82 kx; bo = there is only 3% ash present, their substance must 15.36 k X ; co := 25.69 kX; /3 = 90' 45'. be almost entirely cellulose. I t will he seen that The X-ray value for ao/bo is 0.4440. The there are some indications of a distorted and goniometric value of a / b is 0.4402. The density crumpled fibrillar. structure. Figure 2 shows a calculated from the unit cell constants assuming (1) P. H. Hermans and A. Weidinger, THIS JOURNAL, 68, 2647 (1) Jensen and Lingafelter, THISJOURNAL, 68, 1729 (1946).
(1946).
