Thermal oxidation of PEPA-terminated polyimide

Li, Xiaochen; Miyauchi, Masahiko; González, C.; Nutt, Steven

doi:10.1177/0954008318787852

Cited by 9 publications

(12 citation statements)

References 28 publications

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“…A prior report on thermo-oxidative aging of 4-phenylethynyl phthalic anhydride (PEPA)–end–capped polyimide revealed asymmetric broadening of the tan ( δ ) peak at high aging temperature (316°C), indicating the growth of a thick oxidized layer with more compact packing and wider molecular-weight distribution. 13 This peak-broadening has not been reported for aging of PMR-15. However, similar peak-broadening and shouldering were observed for PETI-340M composites aged at 288°C (indicated by red arrow), although it was not observed after aging at 232°C (Figure 2(a)).…”

Section: Resultsmentioning

confidence: 77%

Thermo-oxidative aging and thermal cycling of PETI-340M composites

Jin

Tsotsis

et al. 2021

High Performance Polymers

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Polyimide composites (PETI-340M) were fabricated and subjected to high-temperature aging and thermal cycling to evaluate resistance to degradation. Mechanical-degradation mechanisms and kinetics depended on aging temperature. Aging at 232°C resulted in strength loss due to polymer degradation, while intra-tow cracking was the dominant mechanism during aging at 288°C. Composite panels subjected to thermal-cycling fatigue (−54°C to 232°C) retained mechanical properties without microcracking. However, in regions containing pre-existing fabrication-induced defects (primarily voids), intra-tow microcracks were observed after thermal cycling. Unlike some polyimide composites (PMR-15), oxidative aging effects during thermal cycling were negligible. The thermo-oxidative stability and the retention of mechanical performance after thermal cycling indicates potential for long-term, high-temperature structural applications.

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Section: Resultsmentioning

confidence: 77%

Thermo-oxidative aging and thermal cycling of PETI-340M composites

Jin

Tsotsis

et al. 2021

High Performance Polymers

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“…It is known that the bond dissociation energy of Ar–Ar (450–460 kJ/mol) is greater than that of Ar–CO–Ar (396 kJ/mol) and Ar–O–Ar (330 kJ/mol). As a result, the PIS-A10 displayed relatively higher thermal oxidative stability than the others [ 35 , 36 ].…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the curve fitting results of the Si 2p peaks for PIS-A10 and PIS-T10 after postcuring at 450 °C for 1 h gave the less Q siloxy units along with more D and T siloxy units as compared with that for PIS-O10 after postcuring at 450 °C. It is suspected that the dramatic increase in T g of PIS-O10 after postcuring at 450 °C correlated with the existence of ether groups, which promote the free radical oxidation crosslinking reaction of siloxane structure and thus further improve the T g of the resin [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

“…As shown in Figure 12, the binding energy of Si 2p peaks for PIS-T10 and PIS-A10 were centered at 103.46 and 103.41 eV, respectively, which are slightly lower than that for PIS-O10 after postcuring at 450 • C/1 h (103.59 eV). Moreover, the curve fitting results of the Si 2p peaks for PIS-A10 and PIS-T10 after postcuring at 450 • C for 1 h gave the less Q siloxy units along with more D and T siloxy units as compared with that for PIS-O10 after postcuring at 450 • C. It is suspected that the dramatic increase in T g of PIS-O10 after postcuring at 450 • C correlated with the existence of ether groups, which promote the free radical oxidation crosslinking reaction of siloxane structure and thus further improve the T g of the resin [35]. a E': onset temperature in the storage modulus curve of DMA; tanδ: peak temperature in the tanδ curve; b T 5 and T 10 : 5% and 10% weight loss temperature, respectively; R 700 : residual weight retention at 700 • C.…”

Section: The Effect Of Postcuring Conditions On the Thermal Propertiementioning

confidence: 98%

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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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“…In the presence of oxygen, the mechanisms of thermal polymer degradation become even more complex due to the formation of highly reactive peroxide macroradicals which enable a cascade of degradation reactions [148][149][150].…”

Section: Thermal (Oxidative) Degradationmentioning

confidence: 99%

New High-Performance Materials: Bio-Based, Eco-Friendly Polyimides

Rusu¹,

Abadie²

2021

Polyimide for Electronic and Electrical Engineering Applications

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The development of high-performance bio-based polyimides (PIs) seems a difficult task due to the incompatibility between petrochemical-derived, aromatic monomers and renewable, natural resources. Moreover, their production usually implies less eco-friendly experimental conditions, especially in terms of solvents and thermal conditions. In this chapter, we touch some of the most significant research endeavors that were devoted in the last decade to engineering naturally derived PI building blocks based on nontoxic, bio-renewable feedstocks. In most cases, the structural motifs of natural products are modified toward amine functionalities that are then used in classical or nonconventional methods for PI synthesis. We follow their evolution as viable alternatives to traditional starting compounds and prove they are able to generate eco-friendly PI materials that retain a combination of high-performance characteristics, or even bring some novel, enhanced features to the field. At the same time, serious progress has been made in the field of nonconventional synthetic and processing options for the development of PI-based materials. Greener experimental conditions such as ionic liquids, supercritical fluids, microwaves, and geothermal techniques represent feasible routes and reduce the negative environmental footprint of PIs' development. We also approach some insights regarding the sustainability, degradation, and recycling of PI-based materials.

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Thermal oxidation of PEPA-terminated polyimide

Cited by 9 publications

References 28 publications

Thermo-oxidative aging and thermal cycling of PETI-340M composites

Thermo-oxidative aging and thermal cycling of PETI-340M composites

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

New High-Performance Materials: Bio-Based, Eco-Friendly Polyimides

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