Flame‐resistant polynaphthoylenbenzimidazoles

Русанов, А. Л.; Serkov, Boris; Булычева, Е. Г.; Kolosova, T. N.; Lekae, T. V.; Пономарев, И. И.; Matvelashvili, N. G.

doi:10.1002/masy.19930740123

Cited by 11 publications

(4 citation statements)

References 1 publication

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“…The yields of carbonised products depend on the chemical structures of polymers. 6,7 The smaller the number of flexible `hinge' groups in the polymer molecule the higher the char yield. It is of note that the flammability of poly(ester imides) depends on the method used for their synthesis.…”

Section: Introductionmentioning

confidence: 99%

Combustion of char-forming polymeric systems

Antonov¹,

Reshetnikov²,

Khalturinskij³

1999

Russ. Chem. Rev.

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We have delineated certain important aspects of the use of theoretical Compton profiles for estimating cohesive energy, energy of mixing etc. Inclusion of electron-electron correlation in the calculation of Compton profiles seems to be essential in order to get the correct values of ground state energy differences. We have also done some model calculation for the energy change as a result of 'switching on' correlation in a homogeneous electron gas at zero temperature. Numerical estimates of this 'correlation energy' have been obtained for free-electron-like metals, viz Na and Li.

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Section: Introductionmentioning

confidence: 99%

Combustion of char-forming polymeric systems

Antonov¹,

Reshetnikov²,

Khalturinskij³

1999

Russ. Chem. Rev.

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“…The chemical structure of PNBI includes six isomeric elements due to the possibility of the existence of "cis-" and "trans-" isomers in the condensed system, as well as the growth of the polymer chain through the meta-or a para-positions of the amino groups of the starting tetraamine. PNBI fibers, traditionally prepared from solutions in inorganic acids [4,6,7], can be spun via the environmentally friendly and economically feasible method by heat treatment of fibers based on poly(o-aminophenylene)naphthoylenimide (PANI-O) precursor [8] (Figure 2). In contrast to PNBI, synthesized in polyphosphoric acid at temperatures of 160-200 • C, PANI-O could be synthesized in organic solvents like dimethyl sulfoxide (DMSO) or Nmethyl-2-pyrrolidone (NMP) at room temperature [5].…”

Section: Introductionmentioning

confidence: 99%

Some Specifics of Defect-Free Poly-(o-aminophenylene)naphthoylenimide Fibers Preparation by Wet Spinning

et al. 2022

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A series of model experiments were carried out on drops of poly-(o-aminophenylene)naphthoylenimide (PANI-O) solutions in N-methyl-2-pyrrolidone (NMP) surrounded by a coagulant of different compositions as starting points of defect-free fibers spinning by the wet method. An influence of compositions of dopes and multicomponent coagulants on the diffusion kinetics and drop morphology during coagulation has been investigated. It is shown that the defining parameters of the coagulation process are viscoelastic properties of the polymer solution and the diffusion activity of the coagulant, meaning not only the rate of coagulation but also the presence/absence of macro defects in the resulting fiber. The optimal morphology of as-spun fibers is obtained by coagulation of solution in a three-component mixture containing solvent and two precipitants of different activity (water and ethanol). The chosen coagulating mixture was used for the fiber spinning of PANI-O with different molecular weights dopes, and fibers with sufficiently high strength (~250 MPa), moduli (~2.1 MPa), and elongation at break (50%) were obtained.

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“…In the current paper, the synthesis of the PNBI family is based on polycondensation of aromatic tetraamines and 1,4,5,8-naphthalene tetracarboxylic acid dianhydride via the stage of stable prepolymer-poly-(o-aminophenylene)naphthoylenimide (PANI) preparation [ 4 , 5 , 6 , 7 , 8 ], soluble in N-methyl-2-pyrrolidone (NMP). Subsequent heat treatment of fibers and films spun from prepolymers solutions leads to the formation of heat and fire-resistant materials possessing a record retention temperature of functional properties reaching 450 °C, oxygen index up to 95, resistance to radiation, ultraviolet radiation, and extremely high climatic stability [ 3 , 6 ]. The use of PNBI varnishes in high-temperature electrical engineering [ 7 ] is also of particular interest.…”

Section: Introductionmentioning

confidence: 99%

Solubility, Rheology, and Coagulation Kinetics of Poly-(O-Aminophenylene)Naphthoylenimide Solutions

et al. 2020

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The effect of temperature and storage time at a constant temperature on the stability of poly-(o-aminophenylene)naphthoylenimide solutions in N-methylpyrrolidone has been analyzed using rotational rheometry. A temperature–time window beyond which an irreversible change in the viscoelastic properties of solutions due to cumulative reactions of continuous polymerization and possible intramolecular cyclization has been detected. The influence of polymer concentration and its molecular weight on the rheological properties of solutions determining the choice of methods for their processing into fibers and films has been investigated. The effect of non-solvents (water and ethanol) additives on the rheological properties of solutions and the kinetics of their coagulation has been studied. Dosed addition of non-solvent into the solution promotes a significant increase in the viscoelasticity up to gelation and phase separation. Non-solvent presence in the polymer solutions reduces the activity of the solvent, accelerates the movement of the diffusion front at coagulation, and minimizes the number of macro defects. The combination of parameters under investigation renders it possible for the first time to develop new principles modifying dopes for wet spinning into aqueous or ethanol coagulation bath and finally to obtain a heat- and fire-resistant polynaphthoylenebenzimidazole fibers.

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Flame‐resistant polynaphthoylenbenzimidazoles

Cited by 11 publications

References 1 publication

Combustion of char-forming polymeric systems

Combustion of char-forming polymeric systems

Some Specifics of Defect-Free Poly-(o-aminophenylene)naphthoylenimide Fibers Preparation by Wet Spinning

Solubility, Rheology, and Coagulation Kinetics of Poly-(O-Aminophenylene)Naphthoylenimide Solutions

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