Synthesis and characterization of a high temperature thermosetting polyimide oligomer derived from a non-toxic, sustainable bisaniline

Harvey, Benjamin G.; Yandek, Gregory R.; Lamb, Jason T.; Eck, William S.; Garrison, Michael D.; Davis, Matthew C.

doi:10.1039/c7ra02182h

Cited by 20 publications

(18 citation statements)

References 24 publications

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“…Polyimides based on dianilines derived from p -cymene had much lower water uptake (3.0 wt%) than these polymers because the addition of an isopropyl substituent in addition to the o -methyl functionality increases the hydrophobicity more significantly. 29 This conclusion that hydrophobicity is of key importance is also supported by recent studies of epoxy-amine networks. 57 Yet, polymers of o -methyl MDA had an even lower water absorption than polymers of 6,6′-methylenebis(3-methylaniline).…”

Section: Resultssupporting

confidence: 55%

“…This could be a result of additional cross-linking of the material or polymer degradation. 29 Our trials have indicated that cure is complete after 2 h in these small samples. Yet, those studies were performed at cure temperatures of no higher than 316°C.…”

Section: Resultsmentioning

confidence: 82%

“…In other words, larger alkyl chains were found to decrease the density. 29 It is likely that larger substituents like ethyl, propyl, and methoxy significantly may disrupt some of the π-stacking of the benzene rings in the cured state leading to more free volume in the network, thus a lower density.…”

Section: Resultsmentioning

confidence: 99%

“…Briefly, the Ames test measures whether a chemical causes mutagenicity in Salmonella bacteria. 29 The Salmonella typhimurium tester strains, TA100 and TA98 (ANIARA, Mason, OH, USA), are dependent on histidine for growth due to errors in a critical gene. 30 If, after exposure to the chemical, the strains are capable of growth in medium without histidine, the chemical has caused changes to the critical gene and is considered mutagenic.…”

Section: Methodsmentioning

confidence: 99%

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The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

Scala

Yandek

Lamb

et al. 2020

High Performance Polymers

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4,4′-Methylenedianiline (MDA) is widely used in high-temperature polyimide resins, including polymerization of monomer reactants-15. The toxicity of MDA significantly limits the manufacturability using this resin. Modifying the substitution and electronics of MDA could allow for the reduction of toxicity while maintaining the high-performing properties of the materials derived from the modified MDA. The addition of a single methyl substituent, methoxy substituent, location of these substituents, and location of the amine relative to the phenolic bridge were modified as were other non-aniline diamines. Various anilines were condensed with paraformaldehyde under acidic conditions to yield dianilines. These dianilines and diamines were reacted with nadic anhydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in methanol to form the polyamic acid oligomers and heated at elevated temperature to form polyimide oligomers. It was found that the molecular weight of the oligomers derived from MDA alternatives was generally lower than that of MDA oligomers resulting in lower glass transition temperatures ( T gs) and degradation temperatures. Additionally, methoxy substituents further reduce the T g of the polymers versus methyl substituents and reduce the thermal stability of the resin. Methyl-substituted alternatives produced polyimides with similar T gs and degradation temperatures. The toxicity of the MDA alternatives was examined. Although a few were identified with reduced toxicities, the alternatives with properties similar to that of MDA also had high toxicities.

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Section: Resultssupporting

confidence: 55%

Section: Resultsmentioning

confidence: 82%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

Scala

Yandek

Lamb

et al. 2020

High Performance Polymers

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“…Thermosetting polyimide resins have been successfully used as the matrix resin of composites in the manufacture of aviation and aerospace vehicles, owing to their excellent thermal stability, high mechanical properties and good dielectric properties [ 1 , 2 , 3 , 4 ]. However, they are usually difficult to process because of the poor melt fluidity and the volatiles release [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

High Thermally Stable and Melt Processable Polyimide Resins Based on Phenylethynyl-Terminated Oligoimides Containing Siloxane Structure

Liu

Lan

et al. 2020

Materials

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A series of 4-phenylethnylphthalic anhydride (PEPA)-terminated oligoimides were prepared by co-oligomerizing isomeric dianhydrides, i.e., 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 2,3,3′,4′-benzophenonetetracarboxylic dianhydride (a-BTDA) or 2,3,3′,4′-diphenylethertetracarboxylic dianhydride (a-ODPA), with diamines mixture of bis(4-aminophenoxy)dimethyl silane (APDS) and 2,2′-bis(trifluoromethyl) benzidine (TFDB). The effects of siloxane content and dianhydride structure on the rheological properties of these oligoimides and thermal stability of the corresponding cured polyimide resins were investigated. The results indicated that the introduction of the siloxane structure improved the melt processability of the oligoimides, while the thermal stability of the cured polyimide resins reduced. The oligoimide derived from a-ODPA revealed better melt processability and melt stability due to the existence of a flexible dianhydride structure. The oligoimide PIS-O10 derived from a-ODPA gave the lowest minimum melt viscosity of 0.09 Pa·s at 333 °C and showed the excellent melt stability at 260 °C for 2 h with the melt viscosity in the range of 0.69–1.63 Pa·s. It is also noted that the thermal stability of these resins can be further enhanced by postcuring at 400–450 °C, which is attributed to the almost complete chemical crosslinking of the phenyethynyl combined with oxidative crosslinking of siloxane. The PIS-T10 and PIS-O10 resins that were based on a-BTDA and a-ODPA, respectively, even showed a glass transition temperature over 550 °C after postcuring at 450 °C for 1 h.

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

Bassett

Cosgrove

Schmalbach

et al. 2019

J of Applied Polymer Sci

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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.

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Synthesis and characterization of a high temperature thermosetting polyimide oligomer derived from a non-toxic, sustainable bisaniline

Abstract: A high temperature, hydrophobic thermosetting polyimide oligomer has been prepared from a non-toxic, bio-based bisaniline derived from p-cymene.

Cited by 20 publications

References 24 publications

The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

High Thermally Stable and Melt Processable Polyimide Resins Based on Phenylethynyl-Terminated Oligoimides Containing Siloxane Structure

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

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