Preparation and characterization of poly(urethane–imide) films prepared from reactive polyimide and polyurethane prepolymer

Zuo, Min; Takeichi, Tsutomu

doi:10.1016/s0032-3861(98)00726-5

Cited by 98 publications

(54 citation statements)

References 13 publications

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“…20 Upon reaching the theoretical NCO value, the prepolymer chain was extended with BD (1.60 g, 17.58 mmol), and the reaction was continued for another 2 h to complete polymerization. TEA (3.00 g, 29.70 mmol) was finally added for neutralization, and the solution was stirred for 30 min while maintaining the temperature at 55 C. POS-S=PU dispersion was attained by slowly adding water (220 g) to the neutralized acetone solution at 45 C with an agitation speed of 800 rpm. After stirring for 2 h, the reaction mixture was transferred to a rotary evaporator, and THF was removed at 40 C. Organic solvent-free dispersions with 30 wt % solids were obtained (Scheme 2).…”

Section: Synthesis Of Trisilanolphenyl-possmentioning

confidence: 99%

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Zhang

et al. 2013

J of Applied Polymer Sci

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A facile and rapid preparation of 3-(2-aminoethylamino)propylheptaphenylPOSS (AA-POSS), a special phenyl-POSS that contains two functional amino groups (Scheme 1), is demonstrated by the corner-capping method. Then AA-POSS forms a series of novel phenyl-POSS=PU aqueous dispersions. The structure of AA-POSS has been confirmed by Si NMR, and ESI-MS. The POSS=PU hybrid films are studied by Fourier transform infrared spectrometer (FT-IR), gel permeation chromatography (GPC), scanning electron microscope (SEM), X-ray diffraction (XRD) spectra, differential scanning calorimetry (DSC) analysis, and thermal gravimetric analyzer (TGA). FT-IR and GPC are conducted to validate the chemical structure of the hybrid PU. The properties of hybrid films display significant changes with notable increases in T g , thermal properties, tensile strength, as well as surface hydrophobicity. These changes are attributed to the incorporation of novel POSS into PU. Moreover, these significant material property enhancements are achieved at low levels of POSS incorporation (only 4%).

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Section: Synthesis Of Trisilanolphenyl-possmentioning

confidence: 99%

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Zhang

et al. 2013

J of Applied Polymer Sci

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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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209

149

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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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“…Fluorinecontaining polyimides, especially those based on 6FDA, have been of interest because of their excellent physical and optical properties and their solubility in common solvents, enabling their utilization in polymer-polymer blending solutions. [18][19][20][21][22] However, the extremely high glass transition temperature of 6FDA-based polyimides has deterred their widespread application. [20][21][22] Blending PMMA with fluorinecontaining polyimides offers an attractive opportunity for the development of novel materials exhibiting useful combinations of the two materials' respective properties.…”

Section: Introductionmentioning

confidence: 99%

Novel Miscible Blends Composed of Poly(Methyl Methacrylate) and 2,2-Bis(3,4-Carboxyphenyl)Hexafluoropropane Dianhydride-Based Polyimides with Optical Grade Clarity

Kim

2009

Mater. Trans.

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Several blends of polymers that varied concentrations of poly(methyl methacrylate) (PMMA) and polyimides based on 2,2 0 -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) were prepared in film form by solution casting and using various solvents. The miscibility of the blended films was correlated through a differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR), and an image analyzer. DSC thermograms revealed two glass-transition temperatures (T g ) for specimens using tetrahydrofuran (THF) as a casting solvent, indicating immiscibility; on the other hand, samples using methyl chloride (MC) and cyclohexanone showed a single T g , indicating miscibility between the two polymers. The phase separation temperature for the miscible samples showed lower critical solution temperature type (LCST-type) behavior and reached its minimum when the content was about 70 mass% PMMA. Both the transmittance and haze of the miscible blended films were measured according to the American Standards Testing Method (ASTM) specification D1003. The transmittance for 6FDA-6FpDA/PMMA had a value of about 85% in the visual light range. However, 6FDA-6FpDA:DABA 2 : 1/PMMA showed a low transmittance below wavelengths of 550 nm. For haze, all of the films were clear with values of less than 1%. The mechanical scratch resistance was measured by pencil test (ASTM 3363). Increasing the 6FDA-6FpDA polyimide content was found to increase the scratch resistance of the films.

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Preparation and characterization of poly(urethane–imide) films prepared from reactive polyimide and polyurethane prepolymer

Cited by 98 publications

References 13 publications

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

High Performance Polybenzoxazines as a Novel Type of Phenolic Resin

Novel Miscible Blends Composed of Poly(Methyl Methacrylate) and 2,2-Bis(3,4-Carboxyphenyl)Hexafluoropropane Dianhydride-Based Polyimides with Optical Grade Clarity

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