Browsing by Subject "Polymers -- Thermal properties"
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Item Solvent determination for thermally stable polymers - PDIAB(Texas Tech University, 1976-05) Dangayach, Kailash C BNot availableItem Thermodynamics of some concentrated solutions of polyethylene oxide.(Texas Tech University, 1974-05) Chang, Yen-huangGas-liquid chromatography (GLC) was used to study the complex solution thermodynamics of concentrated solution of an important water-soluble polymer, polyethylene oxide (PEO). Experimental data from 70°C to 150°C at essentially atmospheric pressure are presented when the solute in PEO solution is at both infinite-dilution and finite concentration. The infinite-dilution volatilites of 14 organic solutes and water in PEO were obtained at each temperature. Activity coefficients of benzene in PEO were also obtained at temperatures from 70°C to 150°C over the polymer concentration range 90 to 100 weight per cent. The corresponding-states theory of polymer solutions initiated by Prigogine and developed by Flory and Patterson was used to correlate our experimental results. Excellent agreement was obtained. Comparison of our infinite-dilution results with the earlier work of Cheng and Bonner (1974) shows some discrepancy. The discrepancy is ascribed to differences in column preparation used in the work of Cheng and Bonner (1974) and in this work. In this work, we account for the effect of PEO degradation of GLC results.Item Thermodynamics of thermally stable polymers - PBI(Texas Tech University, 1976-05) Graham, Alan LymanGas-solid chromatography (GSC) was used to determine the relative solubility of 35 solutes in poly-2, 2'-(meta phenylene)-5, 5'-bibenzimidazole (PBI). Experimental data at 141.8°C, 185°C and essentially atmospheric pressure for each solute in the PBI system at infinite dilution are presented. Pseudo activity coefficients, heats of adsorption (Δh^-∞) and Gibbs energies of adsorption (Δg^-∞ ) were obtained from data taken at 141.8°C and 185°C at essentially atmospheric pressure. Values of Δh and Δg are related to solute polarizability and dipole moment. The significance of the results to polymer solubility is discussed. In addition, the solubility of PBI in four of the previous solutes, acetic acid, 1-butanol, 2,2 ethoxyethanol, and n-decane at 91°C and atmospheric pressure was obtained by static means. Excellent agreement was obtained between the relative solubility of the solutes in PBI predicted by GSC and from the static test data.