The Solvation of High Molecular Substances, Especially Rubber

1930 ◽  
Vol 3 (3) ◽  
pp. 409-417
Author(s):  
P. Stamberger ◽  
C. M. Blow

Abstract 1. On the basis of new experimental data on rubber, the theories of the solvation of high molecular substances are discussed. 2. In this discussion the measurements of the swelling pressure of rubber in toluene are described. The values obtained, and also the measurements of the depression of the vapor pressure lead to the conclusion that rubber cannot be considered a mixture of homologous polymers. 3. The consistency or viscosity of gels is without effect on the decrease in the activity of the solvent (measured by the depression of the vapor pressure and the swelling pressure). 4. The conclusion is drawn that mastication cannot be considered a depolymerization. 5. On the basis of measurements of the viscosity of solutions of rubber-gas black compounds it follows that conclusions as to the molecular weight of the dissolved phase cannot be drawn from viscosity measurements without further ado. 6. The theories of the distribution of high molecular substances in solution are briefly discussed.

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Viorel Feroiu ◽  
Dan Geana ◽  
Catinca Secuianu

Vapour � liquid equilibrium, thermodynamic and volumetric properties were predicted for three pure hydrofluorocarbons: difluoromethane (R32), pentafluoroethane (R125) and 1,1,1,2 � tetrafluoroethane (R134a) as well as for binary and ternary mixtures of these refrigerants. Three cubic equations of state GEOS3C, SRK (Soave � Redlich � Kwong) and PR (Peng � Robinson) were used. A wide comparison with literature experimental data was made. For the refrigerant mixtures, classical van der Waals mixing rules without interaction parameters were used. The GEOS3C equation, with three parameters estimated by matching several points on the saturation curve (vapor pressure and corresponding liquid volumes), compares favorably to other equations in literature, being simple enough for applications.


1957 ◽  
Vol 30 (1) ◽  
pp. 315-325
Author(s):  
R. B. MacFarlane ◽  
L. A. McLeod

Abstract Production of high molecular weight copolymers of butadiene and styrene for use in oil-extended rubbers has aroused interest in the solution properties of copolymers above the molecular weight range commonly encountered in commercial practice. It has been observed that solubility of such polymers in toluene is a time-dependent phenomenon and the apparent solubility can increase continuously, in the absence of agitation, for as long as 800 hours. Although a standard Harris cage solubility test may show the presence of 50% gel, other properties do not confirm the presence of any appreciable quantities of insoluble material. Mild agitation rapidly promotes almost complete solubility. Dilute solution viscosity measurements are very misleading unless the influence of solution time is recognized and apparent intrinsic viscosities rise progressively with time of contact of the sample with solvent. This time-dependence of solution has been found to occur at conversions higher than 50% and is also a function of the amount of modifier used in the polymerization recipe. It has not been possible to shorten the solution time for viscosity measurements by mild heating or gentle agitation. Mixed solvents cause a change in the amount of increase of the apparent intrinsic viscosity but do not shorten the time to equilibrium. Measurement of the slope constant in the Huggins viscosity equation indicate that these solubility and viscosity effects coincide with the appearance of a marked degree of branching in the polymer molecules. The effect is, therefore, interpreted as being caused by the relatively slow disentanglement of molecules of complex structure.


2017 ◽  
Vol 17 (3) ◽  
pp. 500 ◽  
Author(s):  
Rendra Panca Anugraha ◽  
Zul Akbar Andi Picunang ◽  
Annas Wiguno ◽  
Rizky Tetrisyanda ◽  
Kuswandi Kuswandi ◽  
...  

In this work, vapor pressure of binary systems for isooctane + ethanol, isooctane + n-butanol and ethanol + n-butanol and ternary system for isooctane + ethanol + n-butanol were measured in the temperature range from 313.15 to 318.15 K using the inclined ebulliometer. The experimental results showed that the existence of n-butanol in isooctane decreases the vapor pressure of mixture, while increasing n-butanol fraction in ternary isooctane-ethanol-n-butanol mixture decreased vapor pressure of mixture. Experimental data for binary systems studied were correlated with Wilson, NRTL and UNIQUAC models with average relative deviation (ARD) of 3.5%. The optimized binary parameter pairs obtained in this work were used to estimate the ternary system. The Wilson model gave the best performance for estimation of ternary system with ARD of 5.4%. All systems studied showed non-ideal solution with positive deviation from Raoult’s law.


2015 ◽  
Vol 88 (4) ◽  
pp. 574-583 ◽  
Author(s):  
N. V. Ulitin ◽  
K. A. Tereshchenco ◽  
D. A. Shiyan ◽  
G. E. Zaikov

ABSTRACT A theoretical description has been developed of the kinetics of isobutylene with isoprene (IIR) cationic polymerization in the environment of methyl chloride on aluminum trichloride as the catalyst. Based on experimental data on the kinetics of copolymerization (isobutylene conversion curve) and the molecular weight characteristics of the copolymer of IIR, kinetic constants for the process were found. Adequacy of the developed theoretical description of the kinetics of the IIR copolymerization process was confirmed by comparing the experimental molecular-weight characteristics calculated by this description, independent characteristics, and IIR unsaturation.


2011 ◽  
Vol 694 ◽  
pp. 309-314 ◽  
Author(s):  
Jiang Feng Lou ◽  
Rui Xiang Wang ◽  
Min Zhang

The saturated vapor pressures of R22 uniformly mixed with refrigeration oil and nano- refrigeration-oil were measured experimentally at a temperature range from 263 to 333K and mass fractions from 1 to 5%. The experimental results showed that the saturated vapor pressure of R22/KT56 mixture was lower than that of pure R22; the pressure deviation between them increased with a raising mass fraction of refrigeration oil and temperature. After adding nano-NiFe2O4 and nano-fullerene into KT56, the pressure deviation increased at the same mass fraction and temperature. A saturated vapor pressure correlation for R22 and refrigeration oil/nano-refrigeration-oil mixture was proposed, and the calculated values agreed with the experimental data within the deviation of ± 0.77%.


1969 ◽  
Vol 47 (3) ◽  
pp. 267-273 ◽  
Author(s):  
D. H. Bowman ◽  
Ronald A. Aziz ◽  
C. C. Lim

The vapor pressure of liquid argon, krypton, and xenon was measured from below the normal boiling temperature to close to the critical temperature. Functional relations were fitted by a multiple regression analysis to the experimental data. Data of other authors are compared directly with the results presented here.Comparison of the vapor pressure curves for the three liquids showed that the classical corresponding states principle was obeyed only poorly and that it was necessary to include quantum corrections in comparing the reduced curves. The adjusted reduction factors agreed reasonably well with those found from vapor pressure analysis by other workers. De Boer plots on the basis of our potential parameters are more linear than those using the parameters of Boato and Casanova.


2000 ◽  
Vol 123 (4) ◽  
pp. 814-818 ◽  
Author(s):  
G. J. Smallwood ◽  
D. R. Snelling ◽  
F. Liu ◽  
O¨. L. Gu¨lder

The ambiguity and incorrect treatment of the evaporation term among some LII models in the literature are discussed. This study does not suggest that the correct formulation presented for the evaporation model is adequate, or that it reflects the soot evaporation process under intense evaporation. The emphasis is that the current evaporation model must be used correctly in the evaluation of the LII model against experimental data. Numerical results are presented to demonstrate the significance of the molecular weight associated with the heat of evaporation and the thermal velocity of carbon vapor on the results obtained with the evaporation model. Other errors frequently repeated in the literature are also identified.


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