Polyimides and Other High Temperature Polymers: Synthesis, Characterization and Applications, Volume 5

Mittal, Kash L.

doi:10.1201/b12248

Cited by 33 publications

(43 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, both of these dianilines possess ether linkages, producing polyimides with lower glass transition temperatures (T g ) and thermal-oxidative stabilities. 15 Additionally, both 3,4 0 ODA and BAPP demonstrate toxicity equivalent to MDA and are therefore not sustainable alternatives. Another potential dianiline is 2,2 0 -dimethylbenzidine (DMBZ), which is used to produce the DMBZ-15 polyimide.…”

mentioning

confidence: 99%

“…The higher T g is attributed to both the biphenyl linkage that stiffens the molecule, and the addition of methyl groups to the aromatic rings that which limits rotation in the polyimide during the glass transition phase. 15 Yet, the processing characteristics of the resin and toughness of the resulting polymer are worsened. 15 In this work, variety of dianilines were prepared and blended with a commercial curing agent, Epikure W, and cured with EPON 828 [low-molecular-weight oligomer of diglycidyl ether of bisphenol A (DGEBA)].…”

mentioning

confidence: 99%

“…15 Yet, the processing characteristics of the resin and toughness of the resulting polymer are worsened. 15 In this work, variety of dianilines were prepared and blended with a commercial curing agent, Epikure W, and cured with EPON 828 [low-molecular-weight oligomer of diglycidyl ether of bisphenol A (DGEBA)]. It is hypothesized that structureproperty trends for dianilines in epoxy resins will be qualitatively similar in PMR polyimides.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Alternative monomers for 4,4′‐methylenedianiline in thermosetting epoxy resins

Bassett

Cosgrove

Schmalbach

et al. 2019

J of Applied Polymer Sci

View full text Add to dashboard Cite

4,4′‐Methylenedianiline (MDA) is utilized to produce high temperature epoxy resins as well as other high‐performance composites; however, MDA is a known carcinogen and liver toxicant. Novel dianilines derived from both petroleum and biomass with different quantities and types of methyl and methoxy substituents on the aromatic ring were prepared and studied to reduce toxicity and carcinogenic aspects of the resulting material while maintaining thermal and mechanical integrity. These dianilines were primarily prepared by coupling commercial anilines using paraformaldehyde under acidic conditions. Another dianiline was prepared by nitration of bisphenol A and subsequent reduction of the nitrates to amines. Structure–toxicity relationships indicate that multiple substituents on the aromatic ring are necessary to reduce the toxicity of the dianiline. Epoxy‐amine resins were prepared by blending the dianilines with 50 wt % Epikure W liquid amine curing agent and mixing with a stoichiometric amount of EPON 828 epoxy resin. Methoxy and methyl substituents increase the melting point of the dianilines by as much as 65 °C, thereby worsening the processing of these monomers as liquid thermoset resins. Structure–property relationships show that the addition of a methoxy group to the aromatic ring and moving the amine from the 4,4′ position on the dianiline reduces the glass transition temperature (T g) by approximately 10 °C. A single methyl group has little effect on T g and two methyl groups increase the T g only when both are ortho to the amine, yet this causes a large 14 °C increase in T g. Thermal degradation profiles are not significantly affected by the dianiline. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48707.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Alternative monomers for 4,4′‐methylenedianiline in thermosetting epoxy resins

Bassett

Cosgrove

Schmalbach

et al. 2019

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…3,4 Polyimide parts are not affected by many commonly used solvents and oils, such as hydrocarbons and alcohols, which indicates that polyimide can be an excellent coating material at elevated temperature and/or in weathering conditions, such as microelectronics packaging, 5-8 offshore structures, [9][10][11] and aerospace components. [12][13][14] Substrate materials coated by polyimide benefit from its excellent properties, however, there is a need to reduce the thermal expansion and improve permeability and wear resistance of monolithic polyimide coating. The coefficient of thermal expansion of polyimide is related to the linearity of polymer molecular skeletons, 15 thus many researchers have attempted to modify the polymer backbone to reduce the coefficient of thermal expansion, such as incorporating fluorine into the polymer backbone.…”

Section: Introductionmentioning

confidence: 99%

Tribological properties of nanoclay reinforced polyimide nanocomposite coatings for alloy steels

Meng

2017

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

A new process was developed to deposit uniform Montmorillonite nanoclay reinforced polyimide nanocomposite coating on alloy steels. The nanoclay particles were successfully dispersed in N, N-Dimethylacetamide using a combination of magnetic stirring, soaking, and ultrasonic agitation. It was found that the uniform and crack-free coating can be achieved. The tribological tests indicated that the nanocomposite coating has good adhesion to alloy steels, good load carrying capacity, relatively low friction, and wear. This nanocomposite is a promising material for some offshore, aerospace, and automotive structures that are subjected to sliding contact in corrosive environment

show abstract

“…Aromatic polyimides have a variety of engineering and electrical applications due to their reasonably good thermal stability, mechanical properties and chemical resistance, and low dielectric constant. [1][2][3] However, most polyimides encounter processing difficulties because of their low solubility in common organic solvents and high melting or softening temperatures, which strictly limited their applications. Many efforts on the modification of the backbone structure of polyimides with the purpose of obtaining soluble and/or thermoplastic polyimides without sacrificing their excellent thermal and mechanical properties have been devoted to extend the utility of polyimides, such as the incorporation of flexible linkages, bulky pendent groups and aliphatic units, and disruption of their symmetry.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of new poly(ether imides) based on pyridine‐containing aromatic dianhydride and diamine monomers

Wang

Gong

et al. 2009

J of Applied Polymer Sci

View full text Add to dashboard Cite

A series of novel aromatic poly(ether imides) with inherent viscosities of 0.48-0.70 dL/g and weight-average molecular weights of 18,800-40,500 g/mol were successfully prepared from two dianhydride and two diamine monomers containing pyridine moiety via both two-step method and one-step method. Comparison of the one-step and the two-step methods for the preparation of poly(ether imides) was carried out and shown that poly (ether imides) obtained via one-step method exhibited higher molecular weights than the similar polymers prepared through two-step process. Poly(ether imide) resins obtained via both one-step and two-step methods with subsequent chemical dehydration showed good solubility not only in high boiling point solvents but also in low boiling point solvents. High-quality poly(ether imide) films could be obtained via the two-step method with subsequent thermal imidization, which exhibited excellent thermal properties with glass transition temperatures of 239-278 C, initial decomposition temperatures of 540-574 C, residual weight percent at 800 C of 64.5-69.3% under nitrogen, good thermo-oxidative stability with initial decomposition temperatures of 521-544 C, residual weight percent at 800 C of 33.6-51.1% under air atmosphere, outstanding mechanical properties with tensile strengths in the range of 104.6-109.4 MPa, tensile modulus in the range of 1.92-2.58 GPa, and elongation at break from 6.9 to 8.0%, as well as good transparency with cutoff wavelengths of 386-392 nm and low dielectric constants of 2.80-2.92 at 1 MHz.

show abstract

Polyimides and Other High Temperature Polymers: Synthesis, Characterization and Applications, Volume 5

Cited by 33 publications

References 0 publications

Alternative monomers for 4,4′‐methylenedianiline in thermosetting epoxy resins

Alternative monomers for 4,4′‐methylenedianiline in thermosetting epoxy resins

Tribological properties of nanoclay reinforced polyimide nanocomposite coatings for alloy steels

Synthesis and properties of new poly(ether imides) based on pyridine‐containing aromatic dianhydride and diamine monomers

Contact Info

Product

Resources

About