Synthesis and characterization of polymers derived from 2,5‐dimethoxy‐terephthaldehyde and 2,5‐dimethoxy‐terephthalic acid

Abstract

Polyamides were synthesized from 2,5‐dimethoxyterephthaloyl dichloride and diamines. Also, polyimines and polyaldoles were prepared from 2,5‐dimethoxy‐terephthaldehyde with diamines and ketones. The polymers were characterized by elemental analysis and infrared and NMR spectroscopy. Their intrinsic viscosity, glass transition temperature, and thermaldecomposition temperatures were determined.

Conjugated aromatic poly(azomethines). 1. Characterization of structure, electronic spectra, and processing of thin films from soluble complexes

“…A Tt value of 336 °C has been reported for a PHOPI sample with intrinsic viscosity of 0.2 dL/g in concentrated H2S04. 22 The observed multiple transitions for PMPI are similar to prior observations on this polymer11 and were interpreted as due to one crystalline form that is present in a sample with a distribution of crystallite size or degrees of crystal perfection.11 Another possible explanation of this result is thermotropic liquid crystallinity. The lower endotherm in this case would be associated with a crystal to liquid crystalline (LC) phase transition (TCN) and the higher endotherm would be due to LC to isotropic phase transition (TNI).…”

“…2,5-Dimethoxyterephthaldehyde was prepared by a three-step reaction from 1,4-dimethoxybenzene (99%, Aldrich). [22][23][24] The product of each step in the monomer synthesis was characterized by its melting point and *H NMR spectrum. 2,5-Dihydroxyterephthaldehyde was prepared25,26 by reaction of 2,5-dimethoxyterephthaldehyde with a mixture of acetic acid and hydrobromic acid' followed by extraction overnight with benzene in a Soxhlet apparatus.…”

Spectroscopic Investigation of Onset and Enhancement of Electrical Conductivity in PVC/PANI Composites and Blends by γ-ray or UV Irradiation

“…Conducting organic polymers, prepared by both chemical and electrochemical routes, have been the focus of intense scientific activity for the past 10−15 years, and various very successful applications have been reported . To improve the stability/functionality and/or range of applications of these materials, blending or making composites with other polymeric materials has also been successful . Blending or forming composite of polyaniline, PANI, with poly(vinyl chloride), PVC, has been suggested for certain applications…”