The Temperature Dependence of the Osmotic Pressure of Polyvinyl Chloride Solutions¹

Abstract

Temperature Dependence of Osmotic Pressure of Polyvinyl Chloride 1631 of substituents about the double-bonded carbons (RsC=CHR) is reflected in the strong 12.16m band.8 The structure of the low boiling isomer is clearly indicated to be the unconjugated form, 4-methyl-4-penten-2-one, by the fact that the 0=0 band• appears at the normal unconjugated ketone position, 5.83m, and that the strong band in the 10 to 15m region occurs at 11.16m, the position associated with the R20=CHí configuration.® This result is in agreement with the Raman work of Dupont and Menut4 on a mixture of the isomers, the presence of a 1716 cm.-1 line associated with unconjugated 0=0 indicating an unconjugated form.In agreement with chemical evidence referred to in the preceding article, no appreciable concentration of enol form was present as indicated by the weakness of hydroxyl group absorption near 3.0m• The ultraviolet absorption spectra (2100 to 5000 Á.) independently lead to the same conclusion. The high-boiling isomer exhibits bands at 2310 and 3290 Á. (molar extinction coefficients 1.20 X 104 and 40.5 liters/mole cm. respectively; spectra of i-octane solutions). These bands are closely similar in position and intensity to those

The Association of Polymer Molecules in Dilute Solution.

“…The output of the phototube is electronically amplified, and the current produced when light impinges on the tube is determined with a sensitive galvanometer. 5 The instrument, most sensitive to wave lengths at the lower end of the spectrum, has a sensitivity of about 2 X 10-6 foot candles per scale division in the blue region, and this may be increased tenfold by switching out the shunt across the galvanometer.…”

Some Thermodynamic Properties of Polystyrene Solutions.

“…If then a plot of µ against 1/T exhibited any curvature, the terms dropped from equation 6 would have to be reinstated and the values of ß and a given here revised. However, in view of the absence of this effect in polyvinyl chloride solutions (5) it is unlikely that it could be large enough here to greatly affect the ß-and a-values. While the picture presented here is consistent with the observations and moreover implies that the values of /vl calculated from observations on the gels are purely concentration effects, the proposal must be considered as a suggestion to be implemented by further experimental investigation.…”

“…For all other measurements a thermostated dynamic osmometer ivas used. This osmometer and its manipulation have been described previously (5). The probable error in the osmotic pressure measurements is estimated to be between ±0.10 and ±0.20 mm., depending on the concentration and temperature of measurement.…”

The photosensitized polymerization of vinyl chloride in tetrahydrofuran solution III. Determination of the kinetic coefficients

“…The results of Bengough & Norrish (1950) indicate th at chain transfer reactions play an important part in the polymerization. Furthermore, Doty & Mishuck (1947) found th a t the molecular weight of polyvinylchloride determined osmotically, depended on both the solvent used and the temperature. They ascribed this to association and solvation of the polymer molecules.…”