Statistical Thermodynamics of Polymer Solutions Based on Free Volume Theory

1980 ◽  
Vol 13 (3) ◽  
pp. 729-734 ◽  
Author(s):  
Fumiyuki Humada ◽  
Tomoo Shiomi ◽  
Koichi Fukisawa ◽  
Akio Nakajima
Keyword(s):  
Free Volume ◽  
Polymer Solutions ◽  
Statistical Thermodynamics ◽  
Free Volume Theory

Parameters of the free volume theory in glasses with trigonal local coordination

2001 ◽  
Vol 10 (0) ◽  
pp. 147-151
Author(s):  
Т. М. Мельниченко ◽  
Т. Д. Мельниченко ◽  
Я. Я. Коцак ◽  
Я. П. Куценко ◽  
П. П. Пуга
Keyword(s):  
Free Volume ◽  
Free Volume Theory ◽  
Local Coordination

Development of a Method for the Prediction of Pressure-Viscosity Coefficients of Lubricating Oils Based on Free-Volume Theory

1989 ◽  
Vol 111 (1) ◽  
pp. 121-128 ◽  
Author(s):  
C. S. Wu ◽  
E. E. Klaus ◽  
J. L. Duda
Keyword(s):  
Free Volume ◽  
Good Accuracy ◽  
Temperature Relationship ◽  
Free Volume Theory ◽  
Simple Method ◽  
Lubricating Oils ◽  
Viscosity Coefficients ◽  
Data Points

A simple method based on free-volume theory to predict the pressure-viscosity coefficients of liquid lubricants has been developed. The method only requires the viscosity-temperature relationship and the viscosity at the temperature of interest. The method provides good accuracy when it was tested for 162 data points for various fluid types over wide ranges of temperature and viscosity.

Diffusivity of solvents in semi-crystalline polyethylene using the Vrentas-Duda free-volume theory

2018 ◽  
Vol 38 (10) ◽  
pp. 925-931 ◽  
Author(s):  
Derek R. Sturm ◽  
Kevin J. Caputo ◽  
Siyang Liu ◽  
Ronald P. Danner
Keyword(s):  
Free Volume ◽  
Weight Fraction ◽  
Amorphous Region ◽  
Model Parameters ◽  
Crystalline Region ◽  
Free Volume Theory ◽  
Melt Temperature ◽  
Tortuosity Factor ◽  
Crystalline Polyethylene

Abstract Diffusion of penetrants in polyethylene below the melt temperature is heavily dependent on the crystallinity of the polyethylene, the temperature of the experiment, and the concentration of solvent in the polymer. As the crystallinity of the polyethylene increases, there is an increase in the path that the solvent must travel as the solvent cannot penetrate the tightly packed chains in the crystalline domain. This effect is typically accounted for by a tortuosity factor. In this work, a simple and effective characterization of the tortuosity factor based simply on the crystal weight fraction has been developed. Data have been collected for six polyethylenes having densities ranging from 0.912 to 0.961 g/cm3 and for three solvents – isopentane, cyclohexane, and 1-hexene. Diffusivity predictions have been obtained using the free-volume theory of Vrentas and Duda in conjunction with the new tortuosity factor. The polyethylenes had crystallinities varying from 40% to 82% effecting an approximately 60% change in the diffusivity. The decrease resulting from ignoring the crystallinity altogether was in some cases essentially a factor of 5. The error in the predicted diffusivities over all the systems was 25%. For cyclohexane, it is shown that the same model parameters characterize data below the melt temperature (in the semi-crystalline region) as well as above the melt temperature (in the amorphous region).

Free-volume theory coupled with modified group-contribution PC-SAFT for predicting the viscosities. II. Alcohols and their mixtures

2019 ◽  
Vol 502 ◽  
pp. 112298 ◽  
Author(s):  
Dong NguyenHuynh ◽  
My T. Luu ◽  
Xuan T.T. Nguyen ◽  
Chau T.Q. Mai ◽  
Siem T.K. Tran
Keyword(s):  
Free Volume ◽  
Group Contribution ◽  
Free Volume Theory

Solvent self-diffusion, polymer NMR relaxation, and free volume in polymer solutions

1986 ◽  
Vol 24 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Frank D. Blum ◽  
Bojayan Durairaj ◽  
Alapat S. Padmanabhan
Keyword(s):  
Free Volume ◽  
Polymer Solutions ◽  
Nmr Relaxation ◽  
Self Diffusion
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