Novel method for the preparation of poly(urethane-imide)s and their properties

Zuo, Min; Takeichi, Tsutomu

doi:10.1002/(sici)1099-0518(199712)35:17<3745::aid-pola14>3.0.co;2-d

Cited by 76 publications

(48 citation statements)

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“…Alloying with an aromatic polymer such as polyimide has been studied, and proved to be effective for enhancing the thermal properties of PU. [15][16][17] Alloying of PU with polybenzoxazine can be considered as a novel polymer alloy of PU and phenolic resin, in which improvement of both the thermal properties of PU and the toughness of polybenzoxazine can be achieved.…”

Section: Alloying With Polyurethanementioning

confidence: 99%

High Performance Polybenzoxazines as a Novel Type of Phenolic Resin

Takeichi

Kawauchi

Agag

2008

Polym J

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217

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Polybenzoxazines that can be obtained by the thermally induced ring-opening polymerization of cyclic benzoxazine monomers are expected as a novel type of phenolic resins. Various benzoxazine monomers are easily synthesized from mono-or diamines, mono-or bisphenols, and formaldehyde. Polybenzoxazines have not only the advantageous properties of the traditional phenolic resins such as the high thermal properties, but also other properties that are not found in the traditional phenolic resins such as the molecular design flexibility, and excellent dimensional stability. The disadvantages of the typical polybenzoxazines are high temperature needed for the cure and brittleness of the cured materials. Further enhancement of thermal properties is also expected for the applications in harsh conditions. Herein, we report on our various approaches for performance enhancement of the polybenzoxazine, including the designs of novel monomers, high molecular weight polymeric precursors, polymer alloys, and hybrids with inorganics.KEY WORDS: Thermoset / Ring-Opening Polymerization / Thermal Properties / Toughness / Polymer Alloy / Organic-Inorganic Hybrid / Nanocomposite / The traditional phenolic resins possess excellent characteristics such as good heat and chemical resistance, flame retardancy, electrical properties, low water absorption, and low cost due to the inexpensive raw materials and fabricating processes. Therefore, they are widely used in various fields such as structural materials, adhesives, paints and matrix for fiber-reinforced plastics (FRP). Nevertheless, the traditional phenolic resins has many disadvantages including poor shelf life of the precursors, the use of harsh catalyst for polymerization, evolution of volatiles during the cure leading to a large volumetric shrinkage upon cure and formation of voids, and the brittleness of the cured materials. Furthermore, the volatalization of phenol and formaldehyde into the air during the cure process causes some health concern.A series of polybenzoxazine has been developed as a novel type of phenolic resin.1 It differs from the traditional phenolics in that the phenolic moieties are connected by a Mannich base bridge [-CH 2 -N(R)-CH 2 -] instead of methylene (-CH 2 -) bridge associated with the traditional phenolics. The structure of a typical benzoxazine monomer (B-a) prepared from bisphenol-A, aniline and formaldehyde along with the structure of its polybenzoxazine (PB-a) are shown in Figure 1. The monomers for polybenzoxazines are easily prepared from phenols, primary amines and formaldehyde. The wide variations of raw materials, phenols and amines, allow tremendous molecular-design flexibility for the cyclic monomers. Polymerization proceeds through the ring-opening of the cyclic monomers only by heat treatment without the need of catalysts and without generating byproducts or volatiles, and thus offering an excellent dimensional stability for the cured product.Polybenzoxazines provide characteristics found in the traditional phenolic resins such as excellent...

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Section: Alloying With Polyurethanementioning

confidence: 99%

High Performance Polybenzoxazines as a Novel Type of Phenolic Resin

Takeichi

Kawauchi

Agag

2008

Polym J

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217

150

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“…After being dried at 50°C for 16h in vacuo, the films were thermally treated, as fixed on the glass plate, at 100°C and 200° for 1 h each in vacuo to give poly(urethane-imide) films [14].…”

Section: Preparation Of Poly(urethane-imide) Films and Porous Polyimimentioning

confidence: 99%

“…Recently, we prepared a series of novel poly(urethane-imide) films by a reaction between poly(amide acid) obtained from pyromellitic dianhydnde (PMDA) and oxydianiline (ODA) and polyurethane prepolymer obtained from polyethylene adipate and 2,4-tolylene diisocyanate [14,15]. Then, we succeeded in preparing a series of porous polyimide films by thermally treating the poly(urethane-imide) films utilizing the phase separation between the thermally stable imide component and thermally labile urethane component [16].…”

Section: Introductionmentioning

confidence: 99%

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Preparation and Properties of Porous Polyimide Films Prepared by the Pyrolysis of Poly(urethane-imide) Films.

Takeichi

Yamazaki

Ito

et al. 1999

J. Photopol. Sci. Technol.

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Porous polyimide films were prepared by 2 steps. The first step is the preparation of poly(urethane-imide) films by a reaction between phenol-terminated polyurethane prepolymer and poly(amide acid).Polyurethane prepolymer was prepared from the reaction of polyethylene adipate and hexamethylenediisocyanate. Poly(amide acid) was obtained from pyromellitic dianhydride and oxydianiline. The second step is the pyrolysis of the polyurethane-imide) films. Upon thermal treatment of the polyurethane-imide) films at 300 to 400°C, the thermally less stable urethane domains decomposed, leaving porous polyimide films. The presence of pores was confirmed from the scanning electron microscope of the surface and the cross-section of the films. The size distribution of the pore was narrow. With the increase of urethane content, the size of the pore increased. Tensile measurements revealed that, with the increase of urethane component, tensile modulus did not vary so much, but elongation and thus tensile strength decreased. Viscoelastic analyses showed that all the porous polyimide films had high glass transition temperature at above 400°C, and storage moduli were maintained up to 400°C.

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“…[1,2] As a result, tremendous research efforts have been reported to improve the thermal stability of PUs. Most of the reported approaches are based on copolymerization or blending with other polymers of high thermal stability such as polyimides, [3][4][5][6] polyurea, [7,8] polyamide, [9,10] and polyazomethine. [11] Polyimides are high-performance polymers because of their high thermal and thermo-oxidative stabilities, high transition temperatures, and chemical resistance, insulating, and excellent mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Thermal, fluorescence, and electrochemical characteristics of novel poly(urethane-imide)s

Avcı

Şirin

2013

Designed Monomers and Polymers

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In this study, the novel thermally stable poly(urethane-imide)s (PUIs) were synthesized. The structures of the obtained polymers were confirmed by FT-IR and NMR techniques. The molecular weight distribution parameters of the synthesized PUIs were determined by the size exclusion chromatography (SEC). The synthesized PUIs were also characterized by solubility tests, solution viscosity, TG-DTA, and DSC analyses. Cyclic voltammetry measurements were carried out, and HOMO-LUMO energy levels and electrochemical band gaps (E 0 g ) were calculated from their absorption edges. Additionally, optical band gaps (E g ) were determined by using UV-vis spectra of the materials. Fluorescence measurements were carried out in various concentrated DMSO solutions to determine the optimum concentrations to obtain the maximal PL intensities. Also, morphological characterizations were made by scanning electron microscopy technique.

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Novel method for the preparation of poly(urethane-imide)s and their properties

Cited by 76 publications

References 1 publication

High Performance Polybenzoxazines as a Novel Type of Phenolic Resin

High Performance Polybenzoxazines as a Novel Type of Phenolic Resin

Preparation and Properties of Porous Polyimide Films Prepared by the Pyrolysis of Poly(urethane-imide) Films.

Thermal, fluorescence, and electrochemical characteristics of novel poly(urethane-imide)s

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