Syntheses and properties of polyimides derived from diamines containing 2,5‐disubstituted pyridine group

Xia, Aixiang; Guo, Haiquan; Qiu, Xuepeng; Ding, Mengxian; Gao, Lianxun

doi:10.1002/app.24083

Cited by 29 publications

(30 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…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%

“…Due to the PABZ units contained in PBIA fibers, the PBIA fibers can also complex with HCl. In addition, from the FTIR spectra shown in Figure 3, bands can be seen at 3415 and 1490 cm 21 , which have been attributed to isolated, non-hydrogen bonded NH groups in PABZ units 14 and C5N stretching vibrations in PABZ units, 15,16 respectively. The ratio of I 3415 /I 3300 is used to characterize the change of non-hydrogen bonded NH group in benzimidazole units.…”

Section: Properties Of As-spun Pbia/hcl Complex and Pbia Fibersmentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Properties Of As-spun Pbia/hcl Complex and Pbia Fibersmentioning

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

View full text Add to dashboard Cite

show abstract

“…2‐(4‐aminophenyl)‐5‐aminopyrimidine (PAPRM) and 4,4′‐diaminodiphenyl ether ‐2,2′‐disulfonic acid (ODADS) were synthesized respectively according to the previously reported procedure 31, 32. 1,4,5,8‐Naphthalenetetracarboxylic dianhydride (NTDA) was purchased from Aldrich Chemical Co. All other reagents were purchased from Shanghai Chemical Reagent Plant.…”

Section: Methodsmentioning

confidence: 99%

Preparation and properties of ionic cross‐linked sulfonated copolyimide membranes containing pyrimidine groups

Jin¹,

Li²,

Wang³

et al. 2010

Polymers for Advanced Techs

Self Cite

View full text Add to dashboard Cite

A series of sulfonated copolyimides containing pyrimidine groups (SPIs) were synthesized by random copolymerization of 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTDA), 2‐(4‐aminophenyl)‐5‐aminopyrimidine (PAPRM), and 4,4′‐diaminodiphenyl ether‐2,2′‐disulfonic acid (ODADS). Proton exchange treatment in 1.0 M sulfuric acid solution resulted in ionic cross‐linking of the sulfonated copolymers due to the acid (sulfonic acid)‐base (pyrimidine group) interactions and the membrane with more basic PAPRM moiety could absorb sulfuric acid to favor the proton transfer. The effects of the structure of the diamines on the properties of SPI membranes were evaluated by studying the membrane parameters including water uptake, proton conductivity, water stability, and methanol permeability. The basic pyrimidine groups introduced in the main chains could effectively resist membrane swelling due to the strong interchain interactions through basic pyrimidine groups and sulfonic acid groups. Compared with the corresponding uncross‐linked copolyimides (NTDA/ODADS/ODA), the acid–base copolyimides displayed excellent water stability. The SPI membranes also exhibited improved mechanical properties and decreased methanol permeability. However, the cross‐linked membranes showed lowered proton conductivities than the uncross‐linked ones because a small part of the sulfonic acid groups had been consumed during the cross‐linking process. Copyright © 2010 John Wiley & Sons, Ltd.

show abstract

“…What's more, hydrogen bond, as the strongest physical interaction, is a useful way to improve the mechanical properties [7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of novel polyimide films containing amide groups

et al. 2011

View full text Add to dashboard Cite

A novel diamine monomer 4-amino-N-(4-aminophenyl)-benzamide (DABA) containing amide group was introduced to modify the polyimide of pyromellitic dianhydride (PMDA) and 4, 4′-oxydianiline (ODA) by copolymerization. A series of homo-and co-polyamic acid were synthesized by DABA and ODA in different molar ratio with PMDA, and polyimide films were obtained by thermal imidization. The films were characterized by tensile testing, dynamic mechanical analysis (DMA), thermal gravimetry analysis (TGA), fourier transform infrared (FTIR) and wide x-ray diffraction (WAXD). All of the obtained polyimide films show excellent mechanical properties and thermal stability. With the content of DABA increasing from 0% to 100%, the tensile strength and initial modulus are highly improved from 124.72 MPa and 4.70 GPa to 286.46 MPa and 22.06 GPa respectively. The polyimides have 5% weight loss temperature in the range of 530.0-555.5°C. The glass transition temperatures are in the range of 387.90-409.16°C and the tanδ values decrease from 0.3721 to 0.08316. The results of WAXD and FTIR indicate that the introduction of DABA containing amide group can improve the order degree of macromolecule and form hydrogen bonds between the main chains, which results in the improvement of mechanical properties.

show abstract

Syntheses and properties of polyimides derived from diamines containing 2,5‐disubstituted pyridine group

Cited by 29 publications

References 28 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

Preparation and properties of ionic cross‐linked sulfonated copolyimide membranes containing pyrimidine groups

Preparation and characterization of novel polyimide films containing amide groups

Contact Info

Product

Resources

About