摘要:

Electrolyte concentration, rather than pH, concentration of resin particles, or dispersity, is the most significant variable affecting the mobility of polyvinyl acetate emulsions. The mobility–electrolyte concentration curves for latices prepared with nonionic and mixed nonionic and anionic emulsifiers, indicate micelle formation at low electrolyte concentrations. Zeta potentials calculated for a typical latex show the potential drop in the double layer to be of the order of 10−7volts for a variation of thickness of the ionic atmosphere from 10−5to 10−6 cm. over the range of salt concentration used.

ISSN:0008-4042    

DOI:10.1139/v53-129

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Water vapor at room temperature and at pressures in the neighborhood of 10 mm. Hg behaves as a vacuum to each of the three gases hydrogen, helium, and argon, at pressures up to about 100 mm. Hg. The thermodynamic potentials of constituent gases in such mixtures of water vapor and hydrogen, water vapor and helium, etc. probably do not differ from those of the pure components, at equal volume concentrations, by more than 0.3%. Thus these gas mixtures obey the Gibbs–Dalton Law very closely and accordingly must also obey Dalton's Law. Velocity distribution functions of these gases under our experimental conditions are essentially Maxwellian.

ISSN:0008-4042    

DOI:10.1139/v53-130

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The dielectric constants of ethyl chloride andn-butane adsorbed on nonporous TiO2were measured. The plot of capacity change versus volume adsorbed was found to reveal two linear sections in the case of ethyl chloride with an abrupt change in the slope of the plot occurring at theVmvalue calculated using the B.E.T. or Hüttig adsorption equations. Withn-butane the plot was linear beyondVm. For ethyl chloride on rutile a slight temperature dependence in the polarization was observed for the volume of gas adsorbed aboveVm, while a negligible temperature dependence was noted for the portion belowVm. It is postulated that the observations with the polar gas on the nonporous rutile can be explained by a change from oscillatory to rotational motion of the adsorbed molecule after the monolayer is complete. It was noted that gases adsorbed on nonporous TiO2behaved differently from gases adsorbed on porous silica gel. This appears to lead to the necessity of postulating changes of density for the adsorbed phase on silica gel.

ISSN:0008-4042    

DOI:10.1139/v53-131

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The spectra of several isomeric oximes in the solid state were examined in the range 700–3600 cm−1. The associated OH stretching frequency near 3250 cm.−1in the α oximes is displaced towards lower frequency in the β oximes. The region of the OH stretching mode of several oximes was also studied in benzene and chloroform solutions. The frequencies near 1300 cm.−1and 920 cm.−1are tentatively assigned to the OH deformation and the N-OH stretching modes, respectively. No consistent differences are observed between the α and the β oximes with respect to these vibrations. The band at approximately 1640 cm.−1ascribed to the C==N vibration remains essentially unchanged in the spectra of the two isomeric forms.

ISSN:0008-4042    

DOI:10.1139/v53-132

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Electrical conductivities of some molten oxides have been determined. In order of decreasing equivalent conductances at their melting points the oxides investigated were: Li2O, PbO, TeO2, MoO3, Bi2O3, V2O5, Sb2O3, and CrO3. The variation of the observed values of the specific conductivities,K, with the absolute temperature,T, can be described by an equation of the form,whereA,B,C, etc. are constants. While the experimental data are adequately described by an equation of this form containing only the constantsAandB, a slightly better fit is obtained using three constants. The conductivities of the molten oxides follow a pattern of variation from element to element which is substantially the same as that of the molten halides. For elements giving more than one oxide stable in the molten state, the oxide corresponding to the highest state of valency has the lowest conductivity.

ISSN:0008-4042    

DOI:10.1139/v53-133

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

2-Fluoro-5-nitropyridine has been synthesized and its properties compared with 2,4-dinitro-fluorobenzene. Absorption spectra are given. The highly reactive compound was used to prepare well defined derivatives from alcohols, amines, and amino acids.

ISSN:0008-4042    

DOI:10.1139/v53-134

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Monosubstituted benzoylacetic esters, obtained by condensation ofn-alkyl halides with ethyl benzoylacetate, were reacted with hydrazine and phenylhydrazine to give 3-phenyl and 1,3-diphenyl 5-pyrazolones monosubstituted in position 4 by alkyl radicals R (R = H, CnH2n+1(n-1 to 10), and C6H5CH2.). The dissociation constants of the pyrazolones were determined by potentiometric titrations. A study was made of the ultraviolet absorption spectra in both neutral and acid medium and of the infrared absorption spectra. X-ray powder diffraction patterns and data of the pyrazolones were obtained.

ISSN:0008-4042    

DOI:10.1139/v53-135

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Reaction of 3,4,6-triacetyl-β-D-glucopyranosyl chloride with silver acetate in acetic acid gave 1,3,4,6-tetraacetyl-α-D-glucopyranose, m.p. 97–98 °C., [α]D + 145° (chloroform). 3,4,6,-Triacetyl-α-D-glucopyrartosyl chloride, m.p. 93–94 °C., [α]D + 185° (chloroform), prepared from the β-anomer by isomerization in acetone, with silver acetate in acetic acid gave 1,3,4,6-tetraacetyl-β-D-glucopyranose, m.p. 137–138 °C., [α]D + 26° (chloroform). The structures of these glucose tetraacetates were established by the interconversion of chloroacetyl derivatives.

ISSN:0008-4042    

DOI:10.1139/v53-136

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The nitration of 2-amino-4,6-dimethylpyridine with a mixture of nitric and sulphuric acids gives 4,6-dimethyl-2-nitramino-5-nitropyridine (III). 2-Nitraminopyridine (I), 4-methyl-2-nitraminopyridine (II), and (III) produce with diazomethane methyl derivatives of their tautomeric nitramino and nitrimino forms. Diazoethane gives with (I) both the expected ethyl derivatives. However, from (II) only the ethyl derivative of the nitramino form has been obtained. Diazopropane produces with (I) or (II) the propyl derivatives of the nitramino forms only. The resonance structures of the two tautomeric forms of 2-nitraminopyridine have been advanced.

ISSN:0008-4042    

DOI:10.1139/v53-137

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The twoD-glucose residues in the two main components of the ustilagic acid mixture are shown to be present as β-D-cellobiopyranoside units.

ISSN:0008-4042    

DOI:10.1139/v53-138

出版商:NRC Research Press    

年代:1953

数据来源: NRC