ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
On complete hydrazinolysis of poly(ethylene terephthalate), terephthalomonohydrazide is formed from carboxyl-end terephthaloyl residues in a quantity equivalent to the content of carboxyl endgroups in the polymer. The compound is separated from the reaction mixture by ion exchange and determined photometrically [epsiv;240 in 0.1 N HCl = 16,700 (1000 cm2/mole)]. A COOH determination carried out in this way is endgroup specific and, unlike titration, is not subject to interference by ionogenic fiber additives. Aromatic comonomers with acidic substituents (e.g., 5-sulfoisophthalic acid) in chemically modified, cationically dyeable poly(ethylene terephthalate) are determined simultaneously with the carboxyl endgroups by the same analytical method. In this case, the terephthalamonohydrazide and 5-sulfoisophthalodihydrazide are separated by ion exchange, and the difference in their spectral behavior is used for quantitative determination with the aid of a two-component analysis: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} c_1 {\rm = (6}{\rm .21 }D_{240} {\rm - 1}{\rm .04 }D_{212} ){\rm } \times {\rm 10}^{{\rm - 5}} {\rm mole/l}{\rm .} \\ c_2 {\rm = (2}{\rm .62 }D_{212} {\rm - 0}{\rm .51 }D_{240} ){\rm } \times {\rm 10}^{{\rm - 5}} {\rm mole/l} \\ \end{array} $$\end{document} where c1c2 = concentration of terephthalomonohydrazide and 5-sulfoisophthalodihydrazide, respectively; and D240 D212 = optical density at 240 and 212 nm, respectively. The content of carboxyl endgroups in polyether esters poly(p-(2-ethyleneoxy)-benzoate), is determined on the basis of the p-(β-hydroxyethoxy)benzoic acid [epsiv;258 in 0.1 N HCl = 16,100 (1000 cm2/mole)] liberated from carboxyl-end monomer units by hydrazinolysis. For copolyether esters with p-(β-hydroxyethoxy)benzoic acid as a comonomer, the contents of carboxyl-end terephthalic acid and p-(β-hydroxyethoxy)benzoic acid are determined simultaneously with the acid of a spectrophotometric twocomponent analysis: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} c_1 {\rm = (7}{\rm .65 }D_{240} {\rm - 3}{\rm .27 }D_{258} ){\rm } \times {\rm 10}^{{\rm - 5}} {\rm mole/l}{\rm .} \\ c_2 {\rm = (7}{\rm .91 }D_{258} {\rm - 3}{\rm .49 }D_{240} ){\rm } \times {\rm 10}^{{\rm - 5}} {\rm mole/l.} \\ \end{array} $$\end{document} where c2, c2 = concentration of terephthalomonohydrazide and p-(β-hydroxyethoxy)-benzoic acid, respectively; and D240, D258 = optical density at 240 and 258 nm, respectively.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1974.070180705
Permalink
