摘要:

The method of determining sulphate acid ester in unstabilized cellulose nitrates by hydrolysis in acetone/water solution was evaluated. The precision of duplicate determinations for cotton and wood cellulose nitrates containing about 100% sulphate ester was −0.1 to +5.9% and +0.4 to +9.2%, respectively. With cellulose nitrates containing 69–43% and 69–47% sulphate ester, it was +1.8 to +13.4% and +0.4 to +21.0%. The sulphate acid ester content of both unstabilized cotton and wood cellulose nitrates increased with decreasing nitrogen content.

ISSN:0008-4042    

DOI:10.1139/v58-041

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The absorption spectrum in aqueous solution of the yellow substance formed by the reaction of carbon disulphide and alumina exhibits absorption maxima at 398 and 325 mμ. This yellow color is not due to sodium disulphide as previously proposed since the latter substance showed an entirely different spectrum with shoulders at about 360–375 mμ and 290–300 mμ. The presence ofbothwater and sodium hydroxide in the alumina is necessary for the formation of the yellow color in confirmation of previous work. A study of the gain in weight of the alumina with time of contact with carbon disulphide showed that this reaction begins to level off after about 24 hours. A minimum value for the heat evolved for the alumina–carbon disulphide system was determined as 8.6 cal. per g. of alumina reacting with an excess of carbon disulphide.

ISSN:0008-4042    

DOI:10.1139/v58-042

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Graft polymers of acrylonitrile and acrylamide with from 1 to 20 grafts have been prepared by chain transfer to polymer and by photolysis of a copolymer containing a few per cent of α-chloroacrylonitrile. The intrinsic viscosities and softening points have been measured and the dependence of these properties on the number of grafts observed.

ISSN:0008-4042    

DOI:10.1139/v58-043

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Block polymers of acrylamide and acrylonitrile and of acrylamide and acrylic acid have been prepared by photolysis of polymers with end groups that contained bromine. The intrinsic viscosities and softening points of these polymers have been measured and compared with the viscosities and softening points of random copolymers having the same composition and molecular weight.

ISSN:0008-4042    

DOI:10.1139/v58-044

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

A modification in the employment of the direct current method of measuring conductivities is described. The main objective is that pure metallic probe and current carrying electrodes can be used, thus making it possible to investigate the conductivity of solutions such as hydrogen peroxide, aqua regia, etc. This necessitates a choice of electrodes which are inert to such solutions. An electrometer having an infinite resistance so as to avoid any polarization at the probes, in this case the quadrant electrometer, is described in its use as a null instrument. An accuracy as high as or greater than that of the alternating current method could be obtained. Furthermore, this method entails greater equipment economy and simplicity in apparatus required.

ISSN:0008-4042    

DOI:10.1139/v58-045

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The photolysis of MeCN has been investigated under a considerable range of conditions and a mechanism proposed which accounts satisfactorily for the products found, viz. H2, HCN, C2N2, CH4, C2H6, C2H5CN. Two primary processes occurof which the former is apparently the more important. HCN is formed predominantly by an H atom abstraction of the CN group which is believed to occur through addition to the unsaturated bond with the formation of an unstable inline radical. This and similar intermediates formed by other radicals are proposed to account for several anomalies found in the photochemistry of nitriles.A brief investigation of the photolysis of carbonyl cyanide is reported.

ISSN:0008-4042    

DOI:10.1139/v58-046

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The limiting equivalent conductances of ammonium chloride, ammonium bromide, and ammonium nitrate as well as the limiting ionic conductances of the ammonium and nitrate ions were determined at 35 °C. with a probable error of 0.05%. The values found were180.97 mhos,182.73 mhos,174.21 mhos,88.73 mhos, and85.48 mhos. These values were obtained by the application of the Shedlovsky method of extrapolation to equivalent conductance data, which had been corrected for the hydrolysis of the ammonium ion.Observed equivalent conductances of aqueous solutions of ammonium nitrate at 35 °C., in the concentration range from 0.0002 Nto 10 N, have been compared with those calculated by means of the Wishaw–Stokes and Falkenhagen–Leist equations. The Wishaw–Stokes equation was found to give better agreement with experiment than the Falkenhagen–Leist equation.

ISSN:0008-4042    

DOI:10.1139/v58-047

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The seeds ofMedicagosativa(alfalfa) have previously been shown to contain other bases besides stachydrine. One of these bases has now been isolated and found to be a homologue of stachydrine for which the name homostachydrine is suggested. (—)-Homostachydrine is shown to be identical with the (—)-methyl betaine of pipecolic acid. The synthetic racemate of the betaine of pipecolic acid has similar properties to homostachydrine, and their infrared spectra and X-ray powder diagrams are identical.

ISSN:0008-4042    

DOI:10.1139/v58-048

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The photolysis of azoethane at λ 3660 Å has been reinvestigated. The quantum yield of nitrogen formation was found to be dependent on the azoethane pressure and the temperature, indicating collisional deactivation of excited azoethane molecules.The results confirm the mechanism proposed by Ausloos and Steacie (1). For the activation energy of the addition reaction C2H5 + C2H5N2C2H5a value of 6.0 ± 0.3 kcal./mole has been obtained, assuming a negligible activation energy for the combination reaction of two ethyl radicals.

ISSN:0008-4042    

DOI:10.1139/v58-049

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

4-Methylpiperid-2,3-dione-3-phenylhydrazone failed to undergo ring closure under Fisher–cyclization conditions but rearranged to a more stable form of the phenylhydrazone.Cis–transisomerism is suggested for the two forms.

ISSN:0008-4042    

DOI:10.1139/v58-050

出版商:NRC Research Press    

年代:1958

数据来源: NRC