13676-54-5Relevant articles and documents
Study of Diels–Alder reactions between furan and maleimide model compounds and the preparation of a healable thermo-reversible polyurethane
Truong, Thuy Thu,Nguyen, Ha Tran,Phan, Man Ngoc,Nguyen, Le-Thu T.
, p. 1806 - 1814 (2018)
A study of the reactions between various furan and maleimide model compounds and the effects of reaction conditions was performed, allowing for a proper design and preparation of a thermo-reversible polyurethane (PU) material crosslinked via Diels–Alder (DA) bonds. Thus, a linear polyurethane containing furan groups along the main chain was synthesized and crosslinked with a bismaleimide by means of DA reaction. The obtained thermoset exhibited thermo-reversibility as evidenced by DSC and FTIR microscopy, providing the material recyclability and scratch healability. Optical microscopy, SEM and tensile analysis of a scratched PU film revealed that efficient scratch healing was enabled by heating at 110 °C for 30 min and subsequently keeping at room temperature for 24 h, resulting in an approximately 80% recovery of the pristine mechanical strength. This material is a promising candidate for the development of self-healing coatings.
Synthesis and analysis of thermally degradable polybutadiene containing Diels–Alder adduct
Chang, Sanghoon,Kim, Yongkyun,Park, Haneul,Park, Kwangyong
, p. 1602 - 1609 (2021/10/04)
The thermoreversible Diels–Alder reaction, a type of stimuli-responsive reversible organic reaction, is attractive because its direction can be easily controlled. In this study, the cross-linked Diels–Alder adduct-containing polybutadiene (DAPBD) was synthesized by the SN2 reaction of bromine-terminated polybutadiene with a furan-bismaleimide Diels–Alder adduct, and their thermodegradable behavior was analyzed by thermogravimetric analysis. DAPBD was dissociated by the retro-Diels–Alder reaction and dissolved in chlorobenzene at 132 °C to generate furan-terminated polybutadiene (FTPB) and bismaleimide that were identified by 1H NMR spectroscopy. This synthetic method using premade Diels–Alder adducts is expected to enhance the thermoreversibility of the materials by significantly increasing the concentration of the Diels–Alder adduct moieties in the final DAPBD. The polymerization performed at 35 °C will help widen the scope of the use of such materials.
Thermal and electrical behavior of hybrid thermosets based on epoxy and maleimide resins cured with p-aminobenzoic acid
Mustata, Fanica,Tudorachi, Nita,Asandulesa, Mihai,Bicu, Ioan
, p. 799 - 814 (2019/08/07)
Two thermoset systems based on maleimides and diglycidyl ether of bisphenol A (DGEBA) cured with p-aminobenzoic acid were characterized in terms of thermal and electrical behavior. Thermal characterization has been undertaken by means of thermogravimetric analysis in nitrogen atmosphere up to 600°C using simultaneous thermogravimetric/Fourier transform infrared/mass spectrometry (TG/FT-IR/MS) analysis. In the first stage of thermal degradation, the global kinetic parameters [activation energy (Ea) and preexponential factor (log A1 (s?1))] were calculated using the isoconversional method of Friedman. The energies variation as well as the shape of the differential thermal analysis curves suggests that the thermal decomposition process occurred in multiple stages. The evolved gases analysis was conducted by simultaneous TG/FT-IR/MS coupled techniques. Dielectric relaxation spectroscopy characterization was also made.
A diphenylmethane bismaleimide synthetic method
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Paragraph 0024-0029, (2019/03/25)
A diphenylmethane bismaleimide synthetic method, in order to maleic anhydride, 4, 4' - diamino diphenyl methane as the raw material, the catalyst is acetic anhydride, acetic acid as the solvent, a microwave reaction, recrystallized to obtain the diphenylmethane bismaleimide. The method of the invention the reaction is simple and easy to control, after treatment is convenient, the target product of the diphenylmethane bismaleimide purity is greater than 98%, overall yield can reach 90% or more, in accordance with the requirements of the green in the chemical industry.
Cardanol based benzoxazine blends and bio-silica reinforced composites: Thermal and dielectric properties
Arumugam,Krishnan,Chavali,Muthukaruppan
, p. 4067 - 4080 (2018/03/21)
In the present work, a novel cardanol based benzoxazine was synthesised by reacting three different amines (aniline (CrAb), N,N-dimethylaminopropylamine (CrDb) and caprolactam modified N,N-dimethylaminopropylamine (CrCb)) with cardanol in the presence of formaldehyde under appropriate experimental conditions. The resulting benzoxazines were characterised for their molecular structure and thermal behaviour using different analytical methods. Among the different systems studied, the tertiary amine derivatives were found to reduce the curing temperature efficiently (CrAb-275 °C > CrDb-265 °C > CrCb-251 °C) and were confirmed by DSC analysis. These cardanol based CrAb benzoxazines were blended with conventional benzoxazines (Bzs) and bismaleimides (BMIs) as binary and ternary systems and their thermal properties were studied. Three different catalysts (4-hydroxy acetophenone, 4-aminophenol, and 4-hydroxyphenyl maleimide) were used to study the effect of lowering the curing temperature. Further, the prepared benzoxazines were reinforced with varying weight percentages (1, 3, 5 and 10 wt%) of bio-silica derived from rice husk to obtain hybrid composites. The dielectric studies of bio-silica reinforced cardanol benzoxazines infer that the values of dielectric constant decreased with increasing wt% of bio-silica. It was further observed that 10 wt% bio-silica reinforced cardanol benzoxazines show the lowest value of dielectric constant of 1.9 at 1 MHz. From the data obtained from the different studies, it is concluded that the blends of cardanol based benzoxazines can be used in the form of sealants, encapsulants, adhesives and matrices in the fields of microelectronics and automobile applications for better performance.
A facile and economical procedure for the synthesis of maleimide derivatives using an acidic ionic liquid as a catalyst
Li, Kai,Yuan, Chao,Zheng, Shijun,Fang, Qiang
experimental part, p. 4245 - 4247 (2012/08/28)
Seven maleimide derivatives were synthesized in good yields and high purity from the corresponding maleamic acids using a Bronsted acidic room temperature ionic liquid (RTIL) as a catalyst. The products were obtained through merely a decanting and removal of the solvent, suggesting that this procedure is superior to the conventional routes, in which the strong organic/inorganic acids were used as the catalysts, as well as a complicated post-processing procedure for the separation and purification of the products was employed.
Synthesis, UV-Vis spectra, and Hammett correlation of some novel bis(dihydropyrrolo[3,4-c]pyrazoles)
Dueruest, Yasar,Yildirm, Muhammet
scheme or table, p. 961 - 973 (2011/10/04)
Twenty-nine novel bis(dihydropyrrolo[3,4-c]pyrazole) derivatives were obtained by reacting C, N-phenyl-substituted nitrilimines generated in situ from corresponding hydrazonyl chlorides with bismaleimides. The structures were elucidated by physical and spectroscopic methods [m.p., Rf, infrared (IR),1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear correlation (HETCOR), nuclear Overhauser effect (NOE), and high-resolution mass spectrometry (HRMS)]. Also, Hammett correlation graphs were obtained between Hammett constants σp and λmax values of bis(pyrrolopyrazoles) carrying p-substituted phenyl-ring-bearing electron-withdrawing and electrondonating groups and discussed in terms of substituent effects. Springer-Verlag 2010.
New polymers with alkylidenesuccinimide structures based on bismaleimides and biscitraconimides
Gaina, Viorica,Gaina, Constantin
experimental part, p. 647 - 652 (2011/10/18)
New polymers containing alkylidenesuccinimide structures prepared from phosphorous ylides of bismaleimides or biscitraconimides and aromatic dialdehydes by the Witting reaction, are reported for the first time in the literature. Phosphorous ylides of bismaleimides or biscitraconimides were synthesized in situ by the reaction of bismaleimide or biscitraconimide or AB monomers containing both maleimide and aldehyde or citraconimide and aldehyde groups with triphenylphosphine in metha-cresol or acetic acid. The structures of monomers and polymers were confirmed by FTIR, 1H-NMR and UV-visible spectroscopy and elemental analysis. The thermal behaviour of polymers was studied by thermogravimetric analysis and differential calorimetric measurements.
A thermally remendable epoxy resin
Tian, Qiao,Yuan, Yan Chao,Rong, Min Zhi,Zhang, Ming Qiu
body text, p. 1289 - 1296 (2010/03/03)
To provide epoxy resin with crack healing capability, an epoxy containing both furan and epoxide groups, N,N-diglycidyl-furfurylamine (DGFA), was synthesized through a two-step approach. When it reacted with N,N′-(4,4′-diphenylmethane) bismaleimide (DPMBM
Bismaleamic acid, bismaleimide and cured product thereof
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, (2009/12/27)
A bismaleamic acid obtained by reacting a bifunctional phenylene ether oligomer diamine, obtained by introducing aromatic amino groups into both terminals of a specific bifunctional phenylene ether oligomer, with maleic anhydride, a bismaleimide obtained from the bismaleamic acid as a raw material, which bismaleimide has high heat resistance, low dielectric characteristics and excellent solvent solubility and exhibits only a small change in dielectric characteristics even in high humidity, a curable resin composition containing the above bismaleimide and a cured product obtained by curing the curable resin composition.
