Polyimides—new high temperature polymers: H‐film, a polypyromellitimide film

Heacock, J. F.; Berr, Claudine

doi:10.1002/pen.760050207

Cited by 5 publications

(3 citation statements)

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“…The obtained values agree quite well with values reported in the literature. Traeger and Salazar [323] reported an activation energy of 163€20 kJ mol 1 for the pyrolysis of Kapton in air, while Heacock and Berr [324] published values between 162 and 165 kJ mol 1 . The same authors reported a two-step process with an activation energy of 232 kJ mol 1 for the thermal degradation of polyimide in helium.…”

Section: C) Refinement At Low Temperature-differences For Imide/aromamentioning

confidence: 98%

Laser Application of Polymers

Lippert

2004

Polymers and Light

148

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Laser ablation of polymers has been studied with designed materials to evaluate the mechanism of ablation and the role of photochemically active groups on the ablation process, and to test possible applications of laser ablation and designed polymers. The incorporation of photochemically active groups lowers the threshold of ablation and allows high-quality structuring without contamination and modification of the remaining surface. The decomposition of the active chromophore takes place during the excitation pulse of the laser and gaseous products are ejected with supersonic velocity. Time-of-flight mass spectrometry reveals that a metastable species is among the products, suggesting that excited electronic states are involved in the ablation process. Experiments with a reference material, i.e., polyimide, for which a photothermal ablation mechanism has been suggested, exhibited pronounced differences. These results strongly suggest that, in case of designed polymers which contain photochemically active groups, a photochemical part in the ablation mechanism cannot be neglected. Various potential applications for laser ablation and the special photopolymers were evaluated and it became clear that the potential of laser ablation and specially designed material is in the field of microstructuring. Laser ablation can be used to fabricate three-dimensional elements, e.g., microoptical elements.Keywords Laser ablation · Ablation mechanism · Photopolymers · Polyimide · Spectroscopy This was not always true, of course. For many years, the laser was viewed as "an answer in search of a question". That is, it was seen as an elegant device, but one with no real useful application outside of fundamental scientific research. In the last two to three decades however, numerous laser applications have moved from the laboratory to the industrial workplace or the commercial market. Lasers are unique energy sources characterized by their spectral purity, spatial and temporal coherence, and high average peak intensity. Each of these characteristics has led to applications that take advantage of these qualities: -Spatial coherence: e.g., remote sensing, range finding and many holographic techniques. -Spectral purity: e.g., atmospheric monitoring based on high-resolution spectroscopies. -and of course the many other applications in communication and storage, e.g., CDs.All of these high-tech applications have come to define everyday life in the late twentieth century. One property of lasers, however, that of high intensity, did not immediately lead to "delicate" applications but rather to those requiring "brute force". That is, the laser was used in applications for removing material or heating. The first realistic applications involved cutting, drilling, and welding, and the laser was little more advanced than a saw, a drill, or a torch. In a humorous vein A.L. Schawlow proposed and demonstrated the first "laser eraser" in 1965 [4], using the different absorptivities of paper and ink to remove the ink without damaging the und...

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Section: C) Refinement At Low Temperature-differences For Imide/aromamentioning

confidence: 98%

Laser Application of Polymers

Lippert

2004

Polymers and Light

148

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“…The maximum decomposition temperature occurs at 546 °C, at which a primary scission process occurs at the imide bonds (C-N), followed by second cleavage (C-C) resulting in the elimination of C=0 groups. 25 The 46% weight loss of BCPI at 651 °C is thought to be the decomposition of imide structures and ketone groups of BCPI, the theoretical value of which is 35% weight loss.…”

Section: Resultsmentioning

confidence: 99%

Characterization and dissolution studies of a benzophenone-containing organic-soluble polyimide

Lee¹,

Yu²,

Lee³

1990

Macromolecules

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“…in detail' 58 ' and it is claimed that it retains useful mechanical and electrical properties from cryogenic temperatures to beyond 500 °C. It does not melt or burn, has a zero strength temperature of above 800 °C and a useful life of 10 years in air at 250 °C is also claimed.…”

Section: Poly(aromatic-lmides)mentioning

confidence: 99%

The Second Century Papers: Looking Ahead in Aeronautics–22

Scanlan¹,

Jones²

1969

Aeronaut. j.

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Strictly many materials such as ceramics, cement and even metals should be classed as polymers since the atoms within them are bound by strong chemical bonds into large groups usually of indefinite size. This article will deal only with the synthetic organic polymers and, in fact, will consider mainly the plastics, little attention being given to rubbers and fibres. The industrial production of synthetic plastics has expanded greatly in the post-war years largely using petroleum as the starting material. The plastics produced do not have good mechanical properties compared, say, to metals and have other limitations such as poor resistance to heat and inflammability.

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Polyimides—new high temperature polymers: H‐film, a polypyromellitimide film

Cited by 5 publications

References 1 publication

Laser Application of Polymers

Laser Application of Polymers

Characterization and dissolution studies of a benzophenone-containing organic-soluble polyimide

The Second Century Papers: Looking Ahead in Aeronautics–22

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