The liquid chromatography of aromatic diamines: analytical and preparative

Liquid chromatographic methods were developed for determining the purity, reactivity, and preparative separation of aromatic diamine isomers used in the synthesis of aromatic polyimides. Approximately 50 diamine isomers were separated on various silica gels using chloroform and/or cyclohexane mobile phases. A linear relationship between pK_b, and log of the capacity factor was discovered for four series of simple aromatic amines. This suggested that the relative basicities of more complex diamine isomers might be established from chromatographic retention data. A chromatographic basicity index for two series of isomers was then proposed and correlated with polymer viscosity measurements. Several parameters which can affect the efficiency of preparative separations of diamine monomers were also evaluated. These parameters included the effect of the column packing technique, flow rate, column diameter and length, adsorbent surface area and particle size, and column capacity. The results of this evaluation indicate that preparative liquid chromatography can be used to prepare highly purified milligram quantities of monomers for polymer synthesis.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1975

Author dc:creator

• Young, Philip Ross

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/65077

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/65077