A.L. Rusanov

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.

Oligophenylquinoxaline-bis-(o-phenylene diamines) and polynaphthoylene benzimidazoles based on them☆

Abstract Polymers containing phenylquinoxaline and naphthoylene benzimidazole cycles obtained from oligophenylquinoxaline-bis-( o -phenylene diamines) and the dianhydride of 1,4,5,8-napthalene tetracarboxylic acid are described. The starting oligomers have a mean value of the polymerization coefficient 2; the polymers synthesized from them are characterized by regular alternation of the phenylquinoxaline and naphthoylene benzimidazole fragments and dissolve in organic solvents. The thermal characteristics of the polymers obtained are presented.

Hydrodynamic and conformational properties of molecules of rigid chain polynaphthoylene imidoquinazoline

Translational diffusion and the viscosity of ten samples of rod-like polynaphthoylene imidoquinazoline in 96% H2SO4 have been investigated. Equations of the Mark-Kuhn-Houwink type have been obtained [ν] = 2.82 × 10−4M1.40±0.05, D = 4.23 × 10−5M−0.80±0.02. It is shown that the hydrodynamic behaviour of the polynaphthoylene imidoquinazoline molecules in 96% H2SO4 may be adequately described by a model of the streamed worm-like spherocylinder with a high equilibrium rigidity A = (1300±300) × 10−8 cm and hydrodynamic diameter of the chain d = (20±5) × 10−8 cm.

Flow birefringence in solutions of rigid chain polynaphthoylene imidoquinazoline

The optical and conformational properties of polynaphthoylene imidoquinazoline molecules, consisting of rigid arimide fragments joined by simple bonds are studied by flow birefringence and viscosity methods. Modern theories of the dynamooptical properties of worm-like chains are used to show that in sulphuric and sulphonic acids they have a worm-like chain conformation with a low degree of coiling: persistence length a = (800 ± 200) A, optical anisotropy of a unit of length β = 26 × 10−17 cm2. The value of a obtained is almost double the corresponding assessment a = 300 A for the para-aromatic analogue, poly-n-benzamide, which is associated with the presence in the chain of the latter of an amide group, which permits deformation.

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.