The liquid–gas interface of oxygen–nitrogen solutions: 1. Surface tension

The capillary method of surface tension measurement has been used to measure the surface tension of oxygen–nitrogen solutions in the temperature range from 80 to 132 K. At temperatures below the nitrogen critical temperature (T_c = 126.2 K) the capillary constant and the surface tension of solutions are smaller than their additive values and vary linearly with the temperature. Experimental data are compared with the results of calculating the surface tension by the theories of Pinnes and Rowlinson.     

Properties of ethylene–propylene–vinyl chloride graft copolymers. I. Viscoelasticity of ethylene–propylene copolymers

The viscoelastic behavior of two different ethylene–propylene copolymers was studied as a function of the molar ratios of the components and the distribution of the lengths of the ethylene and propylene sequences. The glass transition temperatures T_g agree with the values calculated from relations between T_g and component ratio established by other authors. The copolymer with longer ethylene and propylene sequences was found to exhibit a relaxation spectrum with a slope less steep than ?0.5. This broadening is explained by the broader distribution of friction factors of the statistical segments in this copolymer and by differences in crystallike nearest-neighbor packing.     

Corrigendum: Organometallic complexes with biological molecules: VII. Diorgano– and triorgano–tin(IV)[meso–tetra(4–carboxyphenyl)porphinate] derivatives: solid–state,solution–phase structural aspects and in vivo effects

The title of this paper, published in Applied Organometallic Chemistry 11 , 499–511 (1977), was incorrect. The correct version is as above.     

Sulfinylnitriles: Sulfinyl–Metal Exchange–Alkylation Strategies

Adding organolithiums, Grignard reagents, or zincates to sulfinylnitriles triggers a facile sulfinyl–metal exchange to afford N‐ or C‐metalated nitriles. Sulfinyl–magnesium exchange–alkylations efficiently install quaternary and tertiary centers, even in the case of tertiary sulfinylnitriles that contain a highly acidic methine proton. α‐Sulfinylalkenenitriles afford moderately nucleophilic magnesiated nitriles, and the reactivity can be dramatically increased by conversion to the corresponding magnesiates. The sulfinyl‐metal exchange is extremely fast, proceeds efficiently with quaternary, tertiary, and vinylic α‐sulfinylnitriles, and exhibits an exceptional functional group tolerance in nitrile alkylations.     

Polystyrene–glass bead composites: Maxwell–Wagner–Sillars relaxations and percolation

Dielectric spectrometry experiments are performed on a series of polystyrene–glass bead composites with volume filler content from 0 to 50% and with three particle diameters (5 μm, 20 μm, and 90 μm) in order to study the Maxwell–Wagner–Sillars (MWS) relaxations and the percolation phenomena. In the high-temperature region (130 to 220°C), the experimental data give evidence of MWS relaxations for all the composite systems, whatever the bead size and the filler content are. A good agreement is found between the experimental values of the maximum loss factor frequency and the theoretical ones drawn from the van Beek formula, especially for low contents. A percolation phenomenon is shown in the low-temperature region (40 to 120°C) for high-content/low-size composites. The percolation threshold, determined by considering the critical interparticle distance, is below 15.0% for the 5μm glass bead composites and above 47.3% for the 90 μm composites; it lies between 20.5 and 28.6% for the 20 μm composites. Two schematic models, based on a distribution of the sizes and on a random dispersion of the beads, are developed to show how MWS and percolation phenomena can both be observed for the high-content/low-size composites. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1349–1359, 1997