Preparation and properties of highly branched poly(urethane-imide)-epoxy cross-linked copolymer

Hu, Qian; Wu, Xuqiang; Zhou, Baijie; Meng, Fanzhuo; Pan, Jingwen

doi:10.1080/15685551.2013.867568

Cited by 10 publications

(5 citation statements)

References 30 publications

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“…6,7 Imide structures, unlike silicones, simultaneously have high thermal stability and mechanical properties at high temperatures. In earlier works on the copolymerization of the epoxy backbone using imide structures, mostly the effect of the entrance of imide segments based on aromatic anhydrides such as pyromellitic dianhydride, 9,10 benzophenone tetracarboxylic dianhydride, [11][12][13] trimellitic anhydride, [14][15][16] tetra-/hexahydro phthalic anhydride, [17][18][19] and in some cases maleic anhydride derivative imides, 20,21 or terpolymers of epoxy-siliconeimides [22][23][24] have been investigated.…”

mentioning

confidence: 99%

Comparative study on the curing kinetics and thermal properties of a new series of diglycidyl esters of bis(trimellitimide)s

Abbasi

Jannesari

2022

Polymers for Advanced Techs

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The non-isothermal curing behavior of a new series of epoxy-imide resins based on trimellitimide structures, synthesized in a three-step procedure, were evaluated by differential scanning calorimetry. The chemical structures of the synthesized intermediates and their corresponding epoxy-imide resins were characterized and confirmed by Fourier-transform infrared spectroscopy and 1 H-NMR spectroscopy. The imidecontaining resins, also a medium molecular weight bisphenol-A based epoxy (as reference) were cured by dicyandiamide. The variation of apparent activation energies (E α ) with conversion was then calculated by various differential, as well as integral isoconversional methods. Furthermore, the thermal stability of understudied systems was evaluated by thermogravimetric analysis (TGA). The results showed that the determined melting temperatures of epoxy-imide resins were significantly higher than that of the reference one, but were still within the range of powder coating application temperatures. In contrast with the reference, the imide-containing systems showed the dependency of E α as a function of the curing conversion and the values of E α at the onset of their curing reactions were considerably higher than that of another, ca. 111.6-155.4 kJ/mol against 50.7 kJ/mol, which approached the reference value at the end of the curing reactions. The evaluation of reaction mechanisms with the progress of the curing reactions by the methods of Friedman and Malek revealed the traits of autocatalytic behavior, despite the predominance of the nth-order reaction mechanism. The TGA data also showed that the cured epoxy-imide samples had lower degradation rates, extended stability windows, and enhanced flame retardancy compared with the reference resin.

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confidence: 99%

Comparative study on the curing kinetics and thermal properties of a new series of diglycidyl esters of bis(trimellitimide)s

Abbasi

Jannesari

2022

Polymers for Advanced Techs

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“…The scanning rate was 20min -1 , and the differentiate rate was 4cm -1 . 1 H NMR spectrum of the PUIS was recorded by a 600 MHz Bruker AVANCE II NMR spectrometer (Bruker BioSpin Corporation, Switzerland) using N,N-Dimethylformamide-D7 as solvent. The test was operated at room temperature and a frequency of 600 MHz.…”

Section: Ftir Analysismentioning

confidence: 99%

“…It is widely used in the field of transportation, construction, machinery, water conservancy, national defense, and so forth [1]. Segmented PU elastomers are alternating block copolymers consisting of hard and soft segment units.…”

Section: Introductionmentioning

confidence: 99%

Highly heat-resistant silicon-containing polyurethane-imide copolymers: Synthesis and thermal mechanical stability

Hui

2017

European Polymer Journal

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“…Due to its porous nature, low thermal conductivity and high mechanical properties, polyurethane foam (PUF) has been widely applied in the fields of construction, refrigeration, aviation and aerospace . However, PUF is prone to cracking reaction at high temperature and presents poor heat resistance due to thermally unstable groups on its molecules, such as urea, allophanate, carbamate and biuret.…”

Section: Introductionmentioning

confidence: 99%

Highly reinforcing and thermal stabilizing effect of imide structure on polyurethane foam

Hui

2018

Polymer International

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In order to improve the heat‐resistant property of polyurethane foams, a series of polyurethane‐imide foams (PUIFs) with different contents of the imide group were fabricated via the prepolymer foaming method. It was found that the PUIFs showed a closed cellular structure with almost circular cell shapes. With increasing content of imide groups, the cell wall thickness and apparent density of the foams gradually increased, and the cell size showed a trend of first increasing and then decreasing. All foams exhibited a multistage deformation response when subjected to compressive loading, and the compressive strength and modulus of the PUIFs were significantly improved by incorporation of the imide group, increasing by roughly 5500% and 6400% for the PUIF with 34.25 wt% imide groups, indicating the remarkable reinforcing effect of the imide group on the PUIF. TGA and dynamic mechanical analysis showed that with increase of the imide group content the thermal degradation temperatures, the char yield and the degradation activation energy for the PUIFs sharply increased, while the storage modulus (G′) and Tg were obviously improved, reaching 575 MPa and 283 °C respectively, much higher than that of most reported PU foams, indicating the remarkable enhancement of the thermal mechanical stability of the PUIF. The heat insulation of the PUI system was also enhanced by the incorporation of imide groups. Such PUIFs showed potential applications for use in high temperature environments. © 2018 Society of Chemical Industry

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Preparation and properties of highly branched poly(urethane-imide)-epoxy cross-linked copolymer

Cited by 10 publications

References 30 publications

Comparative study on the curing kinetics and thermal properties of a new series of diglycidyl esters of bis(trimellitimide)s

Comparative study on the curing kinetics and thermal properties of a new series of diglycidyl esters of bis(trimellitimide)s

Highly heat-resistant silicon-containing polyurethane-imide copolymers: Synthesis and thermal mechanical stability

Highly reinforcing and thermal stabilizing effect of imide structure on polyurethane foam

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