Synthesis and properties of soluble aromatic polyamides derived from 2,2′-bis(4-carboxyphenoxy)-9,9′-spirobifluorene

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2003-04, Vol.41 (8), p.1160-1166
• Main Authors: Wu, Shen-Chang, Shu, Ching-Fong
• Format: Article
• Language: English
• Subjects: amorphous; Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; polyamides; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; solubility; spirobifluorene; thermal properties
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.10657

The synthesis of a new bis(ether carboxylic acid), 2,2′‐bis(4‐carboxyphenoxy)‐9,9′‐spirobifluorene, in which two orthogonally arranged carboxyphenoxyfluorene entities are connected through an sp3 carbon atom (the spiro center), is reported. The direct phosphorylation polycondensation of this diacid monomer with various aromatic diamines yields aromatic polyamides containing 9,9′‐spirobifluorene moieties in the main chain. The presence of the spiro segment restricts the close packing of the polymer chains and decreases interchain interactions, resulting in amorphous polyamides with enhanced solubility, and high glass‐transition temperatures and good thermal stability are maintained through controlled segmental mobility. The glass‐transition temperatures of these polyamides are in the range of 234–306 °C, with 10% weight losses occurring at temperatures above 530 °C. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1160–1166, 2003 A series of aromatic polyamides containing 9,9′‐spirobifluorene moieties in the main chain have been synthesized via the direct phosphorylation condensation of 2,2′‐bis(4‐carboxyphenoxy)‐9,9′‐spirobifluorene with aromatic diamines. The incorporation of 9,9′‐spirobifluorene units into the polymer backbone results in polyamides with an enhanced solubility due to a decrease in the degree of molecular packing and crystallinity, and high glass‐transition temperatures and good thermal stability are maintained through controlled segmental mobility.