Aromatic copolyamides: Effect of phenylene content on optical, spectral, and solubility properties

Abstract

SynopsisA series of pam-linked phenylene, bis(trifluoromethy1)biphenylene and stilbene copolyamides was synthesized in order to examine the effect of comonomer ratio on absorption spectra, solubility and birefringence. The data clearly showed that decreasing the stilbene content significantly lowered the birefringence and hypsochromically shifted the absorption band. A decrease in the biphenylene content broadened and bathochromically shifted the absorption band and lowered the birefringence and the solubility.

Synthesis of Soluble, Blue-Light-Emitting Rigid-Rod Polyamides and Polyimides Prepared from 2‘,6‘,3‘‘‘,5‘‘‘-Tetraphenyl- or Tetra(4-Biphenylyl)-4, 4‘‘‘‘-diamino-p-quinquephenyl

“…Polyamide PAb showed a reproducible, gradual relaxation which began at approximately 230 °C. This feature can be attributed to a gradual weakening of intermolecular forces as the temperature increased, and this has been observed previously for other rigid-rod polyamides . An analogous behavior was also observed for polyimide PIBb , which exhibited a relaxation starting at 250 °C.…”

“…Therefore, much effort has been made to increase the solubility of rigid-rod polymers. The most common method to achieve this goal is the incorporation of bulky pendent groups along the backbone. − Rod-like polymers which are soluble in organic solvents without the addition of inorganic salts enable not only processing routes such as dry spinning but also open applications in the area of films, coatings, polymer blends, and composites.…”

Molecular Engineering of Liquid Crystalline Polymers

“…Synthetic procedures for the preparation of soluble aromatic polyamides and polyesters were developed mostly by Gaudiana et al [189][190][191][192][193] Their research was recently reviewed. 194 Depending on their structure, these polymers can be either amorphous or liquid crystalline.…”

Synthesis of a Novel Poly(binaphthylene ether) Containing Trifluoromethyl Groups with a Low Dielectric Constant

“…On the basis of the background described above coupled with the effectiveness of 2,2‘-bis(trifluoromethyl)biphenyl unit for decreasing the ε value while maintaining the thermal stability, we have newly designed and synthesized a high-temperature low- k polymer with low tan δ via oxidative coupling of naphthalene rings. This paper describes the successful synthesis of poly[4,4‘-bis(1-naphthyloxy)-2,2‘-bis(trifluoromethyl)biphen-yl] ( 2 ) by oxidative coupling polymerization of a novel naphthyloxy monomer 4,4‘-bis(1-naphthyloxy)-2,2‘-bis(trifluoromethyl)biphenyl ( 1 ) containing trifluoromethyl groups.…”