SYNOPSISAminoalkyl celluloses ( AmACs) were prepared from 6-chlorodeoxycellulose and aliphatic diamines HzN ( CHz),NHz ( m = 2, 4, 6, 8). Their adsorption and desorption of divalent heavy metal ions such as Cu2+, Mn2+, Co2+, Ni2+ and their mixtures were also investigated in detail.Adsorption of metal ions on AmACs was remarkably affected by the pH of the solution, the metal ion and its initial concentration, and also the number of methylene units in the diamines. No adsorption of metal ions occurred on AmACs in strongly acidic solutions. However, metal ions were adsorbed rapidly on AmACs from weakly acidic solutions and the amount of adsorption increased with increasing pH. The effectiveness of AmACs as adsorbents decreased with increasing length of the methylene moiety, and AmAC from ethylenediamine ( m = 2 ) was most effective. The adsorption of metal ions on AmACs was in the order Cu2+ > Ni2+ > Co2+ > Mn2+. Accordingly, their behavior followed the Irving-Williams series and Cu2+ ions were preferentially adsorbed from solutions containing metal ion mixtures. The adsorbed ions were easily desorbed from the AmACs by stirring in 0.1 M HC1.

A series of thermally stable and semiconducting polyazomethines containing 1,3,4‐oxadiazole or 1,3,4‐thiadiazole ring in the polymer backbone were synthesized by the simple solution poly‐condensation of dialdehydes with the preformed nuclei with aromatic diamines under mild conditions. To elucidate the structure and also structure‐property relationships of the polymers, model compounds were prepared under the same reaction conditions. These polyazomethines having a wholly conjugated system were yellow powders and had reduced viscosities up to 0.38 dL/g in concentrated sulfuric acid and electric conductivity as high as 10−11 S cm−1 at room temperature. Thermogravimetry showed that all the polymers were heat resistant up to around 400°C, in both air and nitrogen atmospheres. Their completely black colored charge‐transfer complexes were prepared by iodine‐doping of the polymers. The room temperature conductivity of the polymers was found to be markedly increased up to the orders of 10−6–10−7 S cm−1 upon doping. The highest value attained was 4.8 x 10−6 S cm−1. Comparison of electronic spectra of the polymers with those of the model compounds indicated the π‐electrons in the polymers are extensively delocalized along the polymer main chain.

Two novel fluorine-containing aromatic polybenzimidazoles were synthesized by direct polycondensation of 4,4'-(hexafluoroisopropy1idene)dibenzoic acid with 33-diaminobenzidine tetrahydrochloride and 1,2,4,5-benzenetetramine tetrahydrochloride. The effect of introduction of fluorine on the synthesis and properties of these polymers is discussed. The'new polybenzimidazoles show good solubility in organic solvents, excellent mechanical properties and high thermal stability.

Novel 1,3,4‐thiadiazole‐containing polyazomethines and copolyazomethines were synthesized by the solution polycondensation, in m‐cresol at 25°C, of aromatic dialdehydes, isophthalaldehyde and terephthalaldehyde, with 2,5‐bis (m‐aminophenyl)‐1,3,4‐thiadiazole (BMAT) and with BMAT and aromatic diamines, bis (4‐aminophenyl) ether and 1,5‐diaminonaphthalene, respectively. These polymers were tan yellow to yellow in color and had reduced viscosities up to 0.32 dL/g in concentrated sulfuric acid and electric conductivity as high as 10−9−10−11 S cm−1 at 25°C. All the polymers were insoluble in common organic solvents but dissolved completely in concentrated sulfuric acid and formic acid. However, they were readily hydrolyzed in concentrated sulfuric acid. X‐ray diffraction diagrams showed that the crystallinity of polyazomethines were low, but copolyazomethines were highly crystalline. These azomethine polymers are highly thermally and thermooxidativelly stable and exhibited no appreciable decomposition up to 400°C in both air and nitrogen atmospheres. Doping with iodine dramatically raised the conductivity and produced the dark brown‐ to completely black‐colored semiconductive polymers with a maximum conductivity of the order of 10−5 S cm−1. Electronic spectra of the undoped polymers indicated a large bathochromic shift of the π−π* absorption band (310 nm) due to CN bonds of BMAT. This result suggests that π‐electrons of the polymers are extensively delocalized along the main chain.

Novel 1,3,4‐oxadiazole‐containing polyazomethines were synthesized by the polycondensation of diamines, 2,5‐bis (m‐aminophenyl)‐1,3,4‐oxadiazole (BMAO) and 2,5‐bis (p‐aminophenyl)‐1,3,4‐oxadiazole (BPAO), with aromatic dialdehydes, isophthalaldehyde and terephthalaldehyde, in m‐cresol at 20°C. These polymers were yellow to orange in color and had reduced viscosities up to 1.13 dL/g and electric conductivity as high as 10−11−10−12 S cm−1. All the polyazomethines were insoluble in common organic solvents but dissolved in concentrated sulfuric acid. Thermogravimetry showed that thermal degradation started at around 400°C in air and nitrogen atmospheres. Doping with iodine markedly increased the conductivity and produced the black‐colored semiconductive polyazomethines with a maximum conductivity of the order of 10−6 S cm−1. Electronic spectra of the undoped polymers indicated a large bathochromic shift of the absorption maxima due to CN bonds of the monomer diamines (285 nm for BMAO and 315 nm for BPAO). This suggests that π‐electrons of the polymers are extensively delocalized along the main chain.