A spectroscopic study of the structure of products of chemical transformations of polyacrylonitrile

Glazkovskii, Yu. V.; Mikhailov, P. V.

doi:10.1016/0032-3950(66)90299-1

Cited by 3 publications

(2 citation statements)

References 4 publications

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“…180°C). Acidic reagents 3 such as acetic acid, benzene sulphonic acid, at 85°C, 75% sulphuric acid of 5°C, and at room temperature to 60°C, and alkaline reagents [5][6][7][8][9] such as sodium carbonate, sodium hydroxide, and potassium hydroxide at room temperature to 85°C and sodium metasilicate 10 have been used for the hydrolysis of nitrile groups in PAN.…”

Section: Introductionmentioning

confidence: 99%

Thermal and rheological behavior of acrylonitrile-carboxylic acid copolymers and their metal salt complexes

Bajaj¹,

Bahrami²,

Sen³

et al. 1999

J. Appl. Polym. Sci.

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ABSTRACT:The influence of acrylic, methacrylic, and itaconic acid comonomers in the nitrile oligomerization of acrylonitrile copolymers has been studied by DSC and DSC-FTIR in air and nitrogen atmospheres. Addition of metal salts in poly(acrylonitrileacrylic acid) copolymer, PA on thermal and rheological behavior has also been reported. Incorporation of CuSO 4 , FeSO 4 , ZnSO 4 , and Al 2 (SO 4 ) 3 (1 to 5 wt %) salt in the polymer solution affects its solubility in DMF. The complexes of PA with zinc sulphate, took a longer time to dissolve in DMF, whereas the complexes with Fe(SO 4 ) and Al 2 (SO 4 ) 3 are almost insoluble in DMF, perhaps due to intermolecular crosslinking. Addition of these metal salts to the PA solution also affects its Brookfield viscosity. The viscosity of 10 wt % polymer solution increases from 400 centipoise (Cps) to 1090 Cps for complex with 5% FeSO 4 (on the weight of dope solids) and 690 Cps for Al 2 (SO 4 ) 3 and 906 cps for ZnSO 4 complex. However, for CuSO 4 salt complex this value is 770 Cps. FTIR spectra shows the participation of COOH and CN group in the complex formation, which is responsible for enhanced Brookfield viscosity. Thermal behavior of the polymer-metal salt complex showed that these salts also affect the exothermic reaction. The initiation of cyclization reaction takes place at a lower temperature compared to neat acrylonitrile-acrylic acid copolymer. However, the heat liberated per unit time in N 2 atmosphere in case of neat polymer is 6.3 Jg Ϫ1 min Ϫ1 , which reduces to 5.5 Jg Ϫ1 min Ϫ1 in the case of the PA/Al complex, confirming the role of Al 2 (SO 4 ) 3 in retarding the rate of cyclization reaction.

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Section: Introductionmentioning

confidence: 99%

Thermal and rheological behavior of acrylonitrile-carboxylic acid copolymers and their metal salt complexes

Bajaj¹,

Bahrami²,

Sen³

et al. 1999

J. Appl. Polym. Sci.

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“…' The homogeneous and heterogeneous alkaline saponification of polyacrylonitrile (PAN) has been investigated several times. [2][3][4][5][6] The kinetics of heterogeneous saponification is affected profoundly by the structure of the polymeric substrate. Alkaline saponification carried out under heterogeneous conditions enhances the essential role played by the special features of supermolecular architecture of the polymeric material in these processes.…”

Section: Introductionmentioning

confidence: 99%

Transformations of polymers and copolymers of acrylonitrile during heterogeneous saponification

Geller

Yereshchenko

Zgibneva

et al. 1974

J. Polym. Sci. Polym. Chem. Ed.

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The kinetic and thermodynamic specific features of the process of heterogeneous alkaline saponification of the copolymer of acrylonitrile (92.2%), methyl acrylate (6.3%), and sodium monoithaconate (1.5%) were investigated. Chemical and infrared spectroscopic methods reveal that the saponification of the nitrile groups of copolymer of acrylonitrile proceeds faster to yield amide groups and then slower to yield carboxylate groups. The order of both stages of the process with respect to the accumulation of the respective groups was evaluated. The dependence of the rate of saponification on the packing density of the structural units was demonstrated. With increasing conversion, the fiber structure becomes looser, as demonstrated by density and sorption investigations. If acrylonitrile copolymer is treated with alkali, the carboxylate groups in the polymer substrate accumulate as a result of saponification of the ester groups of the copolymer, while the nitrile groups are predominantly transformed into the amide groups. If the degree of conversion (with respect to the CN groups) is higher than 62.7%, the copolymer abruptly suffers a marked change in its mechanical properties and gradually dissolves. The products of partial saponification of copolymer were investigated by thermomechanical methods and DTA. The polycyclization of the polymer substrate was found to proceed at a temperatures which decreases as the content of the amide groups increases.

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Degradation of the polyacrylonitrile-based UP2W material under cementitious conditions

Tasi,

Szabo,

Gaona

et al. 2024

Applied Geochemistry

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A spectroscopic study of the structure of products of chemical transformations of polyacrylonitrile

Cited by 3 publications

References 4 publications

Thermal and rheological behavior of acrylonitrile-carboxylic acid copolymers and their metal salt complexes

Thermal and rheological behavior of acrylonitrile-carboxylic acid copolymers and their metal salt complexes

Transformations of polymers and copolymers of acrylonitrile during heterogeneous saponification

Degradation of the polyacrylonitrile-based UP2W material under cementitious conditions

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