A.M. Berlin

The synthesis of polynaphthoylene benzimidazoles by high temperature polycyclocondensation in organic solvents

Abstract A number of polynaphthoylene benzimidazoles (PNBA) of large viscosity were synthesized by reacting bis- o -phenylenediamines with napthaline-1,4,5,8-tetracarboxylic acid dianhydrides in organic solvents by acid catalysis; the products were finely disperse powders with a highly developed surface. The composition of the polymers was confirmed by IR and UV spectroscopy. The effect of the solvents and the catalysts on the product has been investigated. The synthesis conditions of a PNBA based on 3,3,4,4-tetraminodiphenyloxide and naphthaline-1,4,5,8-tetracarboxylic acid dianhydride have been optimized by a statistical planning of the experiments.

The hydrodynamic and conformational properties of polynaphthoylenebenzimidazole molecules in solution

Abstract The coefficients of translational diffusion D and intrinsic viscosity [η] of seven samples of polynaphthoylenebenzimidazole have been measured in sulphuric acid. From the experimental [η] and D values, the molecular masses M D v have been calculated for various values of the hydrodynamic invariant A 0 and equations relating [η] and D with M D v have been derived The length of the Kuhn segment, A = ca . 5·0 nm has been determined from the hydrodynamic data. The molecules of the polymer being studied were shown to be in the confirmation of an hydrodynamically impermeable Gaussian coil. The possible mechanisms of molecular chain flexing were discussed for various configurations of the napthoylenebenezimidazole group.

Synthesis of polynaphthoylene benzimidazoles based on dianhydrides of keto- and sulphone-bis-(4,5-dicarboxy-1-naphthyl)☆

Abstract Polynaphthoylene benzimidazoles not described previously were prepared by the interaction of dianhydrides of keto- and sulphone-bis-(4,5-dicarboxy-1-naphthyl) with 3,3′,4,4′-tetraaminodiphenyl ether under conditions of high-temperature catalytic polycyclocondensation and some of their characteristics determined. Compounds of bis-(1′,8′-naphthoylene-1,2-benzimidazole) series simulating these preparations were synthesized. Using the dianhydrides and 2,2-bis-(3,4-diaminophenyl) hexafluoropropane polynaphthoylene benzimidazoles were prepared which are soluble in N-methyl-2-pyrrolidone and phenol type solvents.

Synthesis and study of polynaphthoylene benzimidazoles soluble in organic solvents

Abstract Polynaphtholylene benzimidazole soluble in organic solvents (which had not been described previously) was obtained by acid catalysis by the interaction of 2,2-bis- (3,4-diaminophenyl)hexafluoropropane with naphthalene-1,4,5,8-tetracarboxylic acid dianhydride in organic solvents. The structure of the polymer was confirmed by results of IR, UV spectroscopy and elementary analysis. By casting a polymer solution in a tetrachloroethane : phenol mixture (3 : 1) on a glass substrate films were obtained and some thermal and physico-mechanical properties examined.

Degradation of polynaphthoylene benzimidazoles

Abstract The thermal, thermohydrolytic and thermooxidative degradation of polynaphthoylene benzimidazoles (PNBI) differing in their chemical structures has been investigated in the temperature interval 250–600°. It is shown that at high temperatures PNBI specimens decompose by a radical mechanism, and that the radical degradation is due to random opening of covalent bonds of heterocyclic fragments. Comparable degrees of cyclization were observed for PNBIs prepared in polyphosphoric acid and by means of high-temperature catalytic polycyclocondensation in organic solvents.

Investigation of the mechanical usability of a number of polynaphthoylenebenzimidazoles

Abstract The relaxation properties of a number of polynaphthoylenebenzimidazoles have been investigated and the regions in which the mechanical properties of the polymers may be used have been investigated. These systems have high glass transition temperatures that coincide with the temperatures for the start of intense thermal degradation. It has been shown that particles of polynaphthoylenebenzimidazole powders have a high auto-adhesion so that solid specimens may be formed from them over a wide range of temperatures and pressures.

Bis(1,8-naphthylimides) and bis(1′,8′-naphthoylene-1,2-benzimidazoles) based on new bis(naphthalic anhydrides)

The reaction of bis(naphthalic anhydrides) with aniline and o-phenylenediamine under conditions of hightemperature cyclocondensation in m-cresol in the presence of a catalyst (benzoic acid) gives bis(1,8-naphthylimides) and bis(1′,8′-naphthoylene-1,2-benzimidazoles) which model the elementary units of polyimides and polynaphthoylenebenzimidazoles, respectively.

Synthesis and study of some bis(1?,8?-naphthoylene-1,2-benzimidazoles)

A number of previously undescribed bis(1′,8′-naphthoylene-1,2-benzimidazoles) were obtained by reaction of bis(o-phenylenediamines) with various structures with naphthalic anhydride. Under the same conditions, the reaction of o-phenylenediamine with naphthalene-1,4,5,8-tetracarboxylic acid dianhydride leads to a mixture of cis and trans isomers of bisbenzimidazobenzophenanthrolinedione. The spectral and thermal characteristics of the synthesized compounds were studied.