US EPA

8360354 

Journal Article 

Determination of amino- and carboxyl end-groups in poly(paraphenylene terephthalamide) 

Van Houwelingen, GDB; Aalbers, JGM; De Hoog, AJ 

1980 

0 

Fresenius' Zeitschrift für Analytische Chemie
ISSN: 0016-1152 

300 

2 

112-120 

English 

10.1007/BF00517828 

Two chemical methods are described for the quantitative determination of amino- and carboxyl end-groups in poly(paraphenylene terephthalamide). The amino end-groups are determined by heterogeneous reaction with 1-fluoro-2,4-dinitrobenzene. After washing out the excess of reagent, the modified polymer is dissolved in methanesulphonic acid and the introduced dinitrophenyl group is measured spectrophotometrically. The determination of carboxyl endgroups is based on a quantitative conversion to an amino group, nitrogen and carbon dioxide with sodium azide in 100 % sulphuric acid. The liberated carbon dioxide is determined by potentiometric titration. The standard deviations of the methods are 2.5 mmole COOH/kg and 0.7 mmole NH2/kg within the range of 5-200 mmole/kg. © 1980 Springer-Verlag. 

Best. von Aminogruppen, Carboxylgruppen in Poly(paraphenylen-terephthalamid); Endgruppen; Spektralphotometrie, Potentiometrische Titration