Effect of the chemical structure of aromatic polyimides on their thermal aging, relaxation behavior and mechanical properties

Ragosta, G.; Abbate, Mario; Musto, Pellegrino; Scarinzi, Gennaro

doi:10.1007/s10853-011-6089-0

Cited by 36 publications

(25 citation statements)

References 28 publications

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“…The results of the DMA tests of the moulded PI compositions are shown in Figure . The PI samples show a linear behavior of the storage modulus in the interval of 50–350 °C and a steeper decrease above 350 °C, which is typical for PMDA‐ODA PIs . Since the maximum service temperature for PI plastics is about 315 °C, it is critical to obtain a polymeric material with predictable linear mechanical behavior when developing new bearing materials or other precision construction parts .…”

Section: Results Of the Dma Thermogravimetric Analysis And Tribologmentioning

confidence: 96%

Recycled moulded polyimide materials obtained by high‐energy ball milling

Olifirov

Kaloshkin

Zadorozhnyy

et al. 2018

J of Applied Polymer Sci

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This article presents a method of manufacturing moulding polyimide (PI) from recycling pyromellitic dianhydride‐4,4′oxydianiline PI films. Recycled PI powders were obtained by grinding PI films in high‐energy ball mill. In order to improve the sintering behavior of the recycled PI, a commercial PI powder (trade mark PM‐69) and a liquid PI resin (trade mark SP‐97) were chosen as modifying additions. PI/PM‐69 and PI/SP‐97 compositions were obtained by high‐energy ball mill. Bulk samples were obtained by compression moulding at 400 °C. The mechanical properties of the moulded PI and the reinforcing action of the PM‐69 and SP‐97 are strongly dependent on the mean size of the recycled PI powders. The flexural strength of 87 MPa and the deformation at failure −4.2% were achieved for the moulded PI/SP‐97 (10 wt %) samples. The resulting materials showed linear behavior of elastic modulus in a temperature range of 50–350 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46733.

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Section: Results Of the Dma Thermogravimetric Analysis And Tribologmentioning

confidence: 96%

Recycled moulded polyimide materials obtained by high‐energy ball milling

Olifirov

Kaloshkin

Zadorozhnyy

et al. 2018

J of Applied Polymer Sci

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“…25,26 In brief, 0.01 mol of ODA was first dissolved in 50 mL of NMP at a three-necked flask and stirred under dry nitrogen for 30 min. Then 0.01 mol of ODPA or BPDA was slowly added to the flask in batches within 20 min and intense mechanical stirring was executed for 24 h to afford a polyamic acid (PAA) solution.…”

Section: Preparation Of Polyimidementioning

confidence: 99%

“…According to previous studies, the high performance of PI mainly comes from its chain structure and intermolecular forces. 26,29 In this study, the introduction of Ca 21 as crosslinked points will exert two implications on PI. For one hand, the destructive effect of chain regularity and linearity deteriorate the mechanical properties.…”

mentioning

confidence: 99%

High temperature shape memory polyimide ionomer

Bai

Long

Liu

2016

J of Applied Polymer Sci

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In this work, a high temperature shape memory polymer based on polyimide (PI) ionomer is prepared by introducing ionic crosslinked interaction. The ionic crosslinked points are introduced to polymer networks through the reaction between polyamic acid and calcium hydroxide before thermal imidization. The crosslinked reaction, microtopography, mechanical, thermal, and shape memory properties of PI ionomers are systematically investigated. The results show the introduction of ionic crosslinked interaction could enhance the glass transition temperature, mechanical, and shape recovery performance of ODA-ODPA, a PI. The prepared ionomers exhibit good high temperature shape memory properties around 270 8C. The shape fixation and shape recovery ratio are over 99% and 90%, respectively. This method provided a new sight of preparing high temperature shape memory polymer, which could be used in severe conditions, like aerospace industry field.

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“…It appears around 58, 85, 61 and 69°C for P1, P2 P3 and P4, respectively, at 1Hz. β Transition of polyimides was assigned to the segmental motion in diamine or dianhydride moiety [53,54], but may comprise larger portions of the structural unit that respond in a correlated manner [55,56] or can ultimately involve the entire repeating segment, as it is the case of rigid systems. The intensity of γ and β relaxations of P1-P4 decreases with temperature reflecting an apparent loss of net dipolar correlation with increasing thermal energy.…”

Section: Dielectric Relaxation Behaviourmentioning

confidence: 99%

Local and segmental motion in highly transparent and low-k poly(ether-imide) films

Damaceanu

Brumă

2014

J Polym Res

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One series of poly(ether-imide)s containing oxadiazole units have been studied with respect to the relationship between the chains structure and their physical properties, particularly thermal transitions and dielectric behavior with emphasis on the local and segmental motion, and optical clarity. High-temperature solution polycondensation reactions of an oxadiazole-containing diamine with different bis(etheranhydride)s resulted in easy soluble polymers with high molecular weights. The variation of the real and imaginary parts of the dielectric permittivity in a large frequency range, from 10 to 10 6 Hz, and in a wide temperature domain, from −150 to 250°C of the tough free-standing films prepared from these polymers was registered. The dielectric constant values, measured at room temperature and in the frequency domain of 10 Hz −1 MHz, were lower or comparable with those of Kapton HN film measured under similar conditions. The dielectric spectroscopy data were corroborated with the dynamo-mechanical analysis ones to highlight the subglass and glass relaxations encountered in these polymer films. The γ and β sub-glass viscoelastic and dielectric relaxations were explored in order to understand their molecular origins, being discussed in correlation with polymers repeating unit structure. The optical transparency of the poly(ether-imide) films has been also studied, to survey their potential for use as flexible substrates in electronic and optical devices.

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Effect of the chemical structure of aromatic polyimides on their thermal aging, relaxation behavior and mechanical properties

Cited by 36 publications

References 28 publications

Recycled moulded polyimide materials obtained by high‐energy ball milling

Recycled moulded polyimide materials obtained by high‐energy ball milling

High temperature shape memory polyimide ionomer

Local and segmental motion in highly transparent and low-k poly(ether-imide) films

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