Compared properties of aromatic polyisophthalamides containing 5-(4-acetoxy-benzamido) pendent groups

Abstract

A series of aromatic polyamides containing 5-(4-acetoxy-benzamido) pendent groups have been synthesized and their properties have been characterized and compared with those of related polyamides. The polyamides have weight-and numberaverage molecular weights in the range of 36,680 -65,700 and 12,685-35,490, respectively, and polydispersities in the range of 1.82-3.66. These polymers show good thermal stability comparable to traditional aromatic polyisophthalamides, with initial decomposition temperature between 270 -320°C and glass transition temperature in the range of 230 -270°C. Compared with related polyisophthalamides without any pendent groups, the present polymers show better solubility in certain solvents such as N-methylpyrrolidinone and dimethylacetamide and can be cast from solutions into thin transparent flexible films having dielectric constants in the range of 3.42-4.27. The polymer films display remarkable hydrophilicity, which makes them potential candidates for use as advanced materials in humidity sensors.

Properties of some azo-copolyimide thin films used in the formation of photoinduced surface relief gratings

“…As reported for other polyimides, [44][45][46] and generally for polymers, dielectric constant, 3 0 , decreases with increasing frequency for the investigated copolyimides (Fig. 6).…”

Synthesis and properties of novel poly(coumarin‐amide)s

“…Therefore, several modifications of their chemical structure have been performed to lower their transition temperatures and to enhance their solubility. One approach used for increasing the solubility and processability of these polymers is the insertion of flexible linkages into the polymer backbone, such as, O2, 3, CO4, SO 2 5, S6, CH 2 7, C(CH 3 ) 2 8, and C(CF 3 ) 2 9, 10. These kinked and flexible bridging units are incorporated between aromatic units into the polymer chain on purpose to reduce the chain stiffness and lower the glass‐transition temperatures.…”