The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

Sun, Ning; Liang, Y.; Xu, Zheng; Li, Heng; Jiang, Shaohua; Li, Yibiao

doi:10.1515/polyeng-2012-0028

Cited by 4 publications

(1 citation statement)

References 15 publications

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“…The NH stretching bands of amide and benzimidazole units are observed in the wavenumber interval from 3200 to 3500 cm −1 . The peak located between 1480 and 1490 cm −1 can be assigned to the stretching vibration of C=N in the benzimidazole ring . The peak centered at 3415 cm −1 can be attributed to the stretching vibration of the isolated, non‐hydrogen bonded NH groups in benzimidazole units and the peak centered approximately at 3300 cm −1 is related to the hydrogen bonded NH group .…”

Section: Resultsmentioning

confidence: 99%

Enhancing mechanical properties of aromatic polyamide fibers containing benzimidazole units via temporarily suppressing hydrogen bonding and crystallization

Luo

Huang

et al. 2015

J of Applied Polymer Sci

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The copolymerization modified poly(p-phenylene terephthalamide) containing 2-(4-aminophenyl)25-aminobenzimidazole (PABZ) units in the main chain was synthesized and the corresponding poly-p-phenylene-benzimidazole-terephthalamide (PBIA) fibers were prepared by wet spinning. The HCl, the by-product released during polymerization, can complex with PABZ units to prevent the formation of hydrogen bonding between PABZ units, resulting in amorphous PBIA fibers and a lower glass transition temperature (T g ). Therefore, for the purpose of gaining strong hydrogen bonding and high orientation degree at the same time in PBIA fibers, two-step drawing-annealing processing was adopted. The as-spun PBIA/HCl complex fibers were drawn first at 2808C, higher than the T g of the PBIA/HCl complex fibers and lower than the decomplexed temperature of HCl, which temporarily suppresses the formation of hydrogen bonding and crystallization. Subsequently, the fibers were annealed to reform hydrogen bonding between PABZ units and crystallization via decomplexation of HCl at 4008C. However, when the drawing is above the decomplexed temperature of HCl, the decomplexation of HCl begins to occur which leads to the reform of hydrogen bonding and crystallization, and the tensile strength of the drawn-annealed PBIA/HCl complex fibers decreases with a decrease in the HCl content of fibers. The tensile strength of two-step drawn-annealed fibers increased by approximately 15% compared to that of one-step drawn PBIA/HCl complex fibers.

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Section: Resultsmentioning

confidence: 99%

Enhancing mechanical properties of aromatic polyamide fibers containing benzimidazole units via temporarily suppressing hydrogen bonding and crystallization

Luo

Huang

et al. 2015

J of Applied Polymer Sci

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Kinetic Analysis, Solid Residues and Volatile Products of Pyrolyzing Nomex Insulation Paper in Nitrogen and Air Atmosphere

Zhang¹,

Guo

Chen

et al. 2022

Fire Technol

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Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers

2019

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The man aim of this work was to investigate the effect of the molecular weight of polyols, mixture of prepolymers, and [NCO]/[OH] molar ratio used during the prepolymer chain extending step on the chemical structure, thermomechanical and mechanical properties, and thermal stability of thermoplastic poly(ether-urethane)s In this work thermoplastic poly(etherurethane)s were synthesized by using polyols with a various molecular weight, 4,4′-diphenylmethane diisocyanate and biobased glycol. Materials were obtained by a two-step method. The tests were carried out for polyurethanes obtained from a mixture of prepolymers and for reference samples. In the case of materials obtained with using mixture of prepolymers, the ratio of both prepolymers was determined on 50/50 weight percent. Soft segments of materials prepared with using mixture consist of two different polyols. The chemical structure was analyzed using FTIR spectroscopy. The Gaussian deconvolution technique was used to study the hydrogen bonding as well as to decompose carbonyl region of three peaks in various TPUs. The thermal degradation behavior was investigated by using thermogravimetric analysis at heating rates of 10 °C/ min. It was confirmed that the mixture of prepolymers has an effect of the degree of phase separation, thermal stability and selected properties of synthesized thermoplastic poly(ether-urethane)s.

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The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

Cited by 4 publications

References 15 publications

Enhancing mechanical properties of aromatic polyamide fibers containing benzimidazole units via temporarily suppressing hydrogen bonding and crystallization

Enhancing mechanical properties of aromatic polyamide fibers containing benzimidazole units via temporarily suppressing hydrogen bonding and crystallization

Kinetic Analysis, Solid Residues and Volatile Products of Pyrolyzing Nomex Insulation Paper in Nitrogen and Air Atmosphere

Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers

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