ISSN:
1435-1536
Keywords:
Poly(ethylene oxide)
;
solubility
;
basicity
;
hydroxyl end groups
;
polymer
;
solute interactions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The general solvation equation $${\text{Log }}L = c + r \cdot R_2 + s \cdot \pi _2^{\text{H}} + a \cdot \alpha _2^{\text{H}} + b \cdot \beta _2^{\text{H}} + l \cdot \log {\text{ }}L^{16} $$ has been used to evaluate the effect of molecular weight, hydroxyl end groups and temperature on the solubility characteristics of poly(ethylene oxide), PEO. In this equationL is the gas-liquid partition coefficient of a series of probes on PEO, and the explanatory variables are solute properties describing the excess molar refraction,R 2, the probe dipolarity-polarisability, π 2 H , and the probe hydrogen-bond acidity and basicity, α 2 H and β 2 H .L 16 is the gas-liquid partition coefficient of the probe onn hexadecane at 298 K. Ther·R 2 andl·logL 16 terms increased with increase in molecular weight whereas thes·π 2 H and a α 2 H terms decreased; in all cases theb·α 2 H term was not significant. Since thes-constant is a measure of polymer polarity-polarisability, and thea-constant a measure of polymer basicity, we deduce that these polymer properties decrease with increasing molecular weight. Chains with molecular weight below 3000 showed a more rapid decrease in basicity compared to the higher molecular weight species. Thes·π 2 H ,a·α 2 H andl·logL 16 terms all decreased with increase in temperature. Finally, the contribution of the terminal hydroxyl groups to the total polymer basicity was evaluated and discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00652428
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