Preparation and properties of new soluble aromatic polyimides from 2,2′‐bis(3,4‐dicarboxyphenoxy)biphenyl dianhydride and aromatic diamines

Liou, Guey‐Sheng; Maruyama, Makoto; Kakimoto, Masa–aki; Imai, Yoshio

doi:10.1002/(sici)1099-0518(19980915)36:12<2021::aid-pola7>3.0.co;2-#

Cited by 43 publications

(13 citation statements)

References 17 publications

(13 reference statements)

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“…Considerable research efforts have been focused on the synthesis of soluble polyimides that maintain the excellent properties of this class of compounds 4. Typical approaches include the introduction of bulky lateral groups,5–12 flexible linkages,13, 14 kinked15–20 or unsymmetrical structures21, 22 into the polymer backbone.…”

Section: Introductionmentioning

confidence: 99%

Effect of a closure device on complication rates in high‐local‐risk patients: Results of a randomized multicenter trial

Chevalier

Lancelin

Köning

et al. 2003

Cathet Cardio Intervent

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Clinical trials have shown that coronary stenting is associated with a high level of complications at the access site. Arterial sealing devices have proven their efficacy in obtaining immediate hemostasis after sheath removal, in allowing early ambulation, and in improving patient comfort. However, there is no report showing a reduction of local complications related to their use. The purpose of this multicenter study was to compare randomly the efficacy of Angio-Seal versus compression methods of hemostasis in reducing the rate of access site complications after coronary angioplasty in 612 selected patients with higher risk of local events satisfying at least one of the following high-risk criteria: age> 70, previous puncture at the same site, history of hypertension, treatment with ticlopidine at least 2 days before the procedure, use of abciximab, 8 Fr access, prolonged heparin treatment after the angioplasty, and use of lytics if fibrinogen > 1 g/l. Group A (n = 306) had immediate sheath removal, Angio-Seal implantation, and cessation of bed rest 4 hr after the intervention. Group B (n = 306) had sheath removal according to local practice and cessation of bed rest 6-18 hr after the hemostasis procedure, also according to local practice. Clinical follow-up was done at 1 hr, 4 hr, 24 hr, discharge, and 7 days and a systematic color flow duplex sonography was performed to confirm diagnosis of access site complication. In group A, device deployment and immediate hemostasis were obtained in, respectively, 96.8% and 87% of patients. Time to hemostasis was shorter in group A: 5 vs. 52 min (P < 0.001). Cessation of bed rest was dramatically reduced in group A (438 +/- 450 min) vs. group B (952 +/- 308 min; P < 0.001). The cumulative rate of complications, using a composite primary endpoint, at 7 days was significantly different between the two groups: 5.9% of group A patients and 18% of group B patients (P < 0.001). This difference was mainly due to the dramatic reduction of prolonged bleeding in group A patients. Angio-Seal device use in high-local-risk patients allows immediate sheath removal and hemostasis with a reduction of local event rate despite a higher level of anticoagulation, compared to regular compression techniques, directly related to a dramatic decrease of prolonged bleeding.

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Section: Introductionmentioning

confidence: 99%

Effect of a closure device on complication rates in high‐local‐risk patients: Results of a randomized multicenter trial

Chevalier

Lancelin

Köning

et al. 2003

Cathet Cardio Intervent

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“…To utilize the thermal stability of polyimides for further applications and to take advantage of other properties of these classes of polymers, such as high chain rigidity, packing density, and polar chain interactions for different applications, it is desirable to synthesize soluble and/or melt‐processable variations. Solubilizations of the polyimides have been targeted by several means, such as the introduction of flexible linkages,13–20 bulky substituents21–39 and bulky units within the polymer backbone,40–52 non‐coplanar monomers,53–63 or alicyclic64–72 monomers. The main concept behind all of these approaches is the reduction of several types of polymer chain–chain interactions, reduction of chain packing, and charge‐transfer electronic polarization interactions.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of fluorinated polyimides. 1. Derived from novel 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl

Banerjee

Madhra

Salunke

et al. 2002

J. Polym. Sci. A Polym. Chem.

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A new diamine monomer, 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl (ATFT) was synthesized that led to a number of novel fluorinated polyimides by solution as well as thermal imidization routes when reacted with different commercially available dianhydrides like pyromellatic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), or 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane (6FDA). The polyimides ATFT/BTDA and ATFT/6FDA derived from both routes were soluble in several organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, and dimethyl sulfoxide. The polyimide ATFT/PMDA was only soluble in N‐methylpyrollidone. The polyimide films had low water absorption of 0.3–0.7%, low dielectric constants of 2.72–3.3 at 1 Hz, refractive indices of 1.594–1.647 at 589.3 nm, and optical transparency >85%. These polyimides showed very high thermal stability with decomposition temperatures (5% weight loss) up to 532 °C in air and good isothermal stability; only 7% weight loss occurred at 400 °C after 7 h, and less than 0.6% weight loss was observed at 315 °C for 5 h. Transparent thin films of these polyimides exhibited tensile strengths up to 112 MPa, a modulus of elasticity up to 3.05 GPa, and elongation at break up to 21% depending on the repeating unit structure. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1016–1027, 2002

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“…These properties make them generally intractable or difficult to process, thus limiting their applications. Therefore, incessant efforts have been expended to try to improve the processing characteristics of these relatively intractable polymers 4–18. One of the approaches to increasing solubility and lowering the glass‐transition temperature ( T g ) and T s is the introduction of flexible groups in the polymer backbone 14–18.…”

Section: Introductionmentioning

confidence: 99%

Preparation and properties of new polyimides and polyamides based on 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

Hsiao

Yang

Huang

2004

J. Polym. Sci. A Polym. Chem.

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A novel, trifluoromethyl‐substituted, bis(ether amine) monomer, 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene, was synthesized through the nucleophilic displacement of 2‐chloro‐5‐nitrobenzotrifluoride with 1,4‐dihydroxynaphthalene in the presence of potassium carbonate in dimethyl sulfoxide, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new fluorine‐containing polyimides with inherent viscosities of 0.57–0.91 dL/g were prepared by reacting the diamine with six commercially available aromatic dianhydrides via a conventional, two‐step thermal or chemical imidization method. Most of the resulting polyimides were soluble in strong polar solvents such as N‐methylpyrrolidone and N,N‐dimethylacetamide (DMAc). All the polyimides afforded transparent, flexible, and strong films with good tensile properties. These polyimides exhibited glass‐transition temperatures (Tg's) (by DSC) and softening temperatures (by thermomechanical analysis) in the ranges of 252–315 and 254–301 °C, respectively. Decomposition temperatures for 5% weight loss all occurred above 500 °C in both air and nitrogen atmospheres. The dielectric constants of these polyimides ranged from 3.03 to 3.71 at 1 MHz. In addition, a series of new, fluorinated polyamides with inherent viscosities of 0.32–0.62 dL/g were prepared by the direct polycondensation reaction the diamine with various aromatic dicarboxylic acids by means of triphenyl phosphite and pyridine. All the polyamides were soluble in polar solvents such as DMAc and could be solution‐cast into tough and flexible films. These polyamides had Tg's between 228 and 256 °C and 10% weight‐loss temperatures above 400 °C in nitrogen or air. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2377–2394, 2004

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Preparation and properties of new soluble aromatic polyimides from 2,2′‐bis(3,4‐dicarboxyphenoxy)biphenyl dianhydride and aromatic diamines

Cited by 43 publications

References 17 publications

Effect of a closure device on complication rates in high‐local‐risk patients: Results of a randomized multicenter trial

Effect of a closure device on complication rates in high‐local‐risk patients: Results of a randomized multicenter trial

Synthesis and properties of fluorinated polyimides. 1. Derived from novel 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl

Preparation and properties of new polyimides and polyamides based on 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

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