Bismaleimide-triazine Resins Research Articles

Development of Radiation-Resistant Warm Magnets Using Cyanate Ester Resin

We have been developing radiation-resistant warm magnets insulated by cyanate ester (CE) resins. A glass fiber cloth prepreg tape was fabricated using CE pre-polymers supplied by Mitsubishi Gas Chemical Company Inc. Proton beam irradiation tests were carried out for evaluation of the radiation hardness. We prepared cured resin samples of cyanate ester, bismaleimide triazine (BT), and epoxy resins using the same glass fiber cloth. The resin samples were irradiated by a 70-MeV proton beam at doses up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> Gy at the Cyclotron and Radioisotope Center, Tohoku University. The results of tensile tests after irradiation showed that the radiation resistance of the CE resins was almost same as that of BT resins and more than 10 times as high as that of epoxy resins. We also developed a CE putty for use in coil moldings. A curing test was performed on a coil mock-up made of a stack of hollow conductors wrapped with the CE prepreg tapes and putty. We successfully cured the coil mock-up without causing thermal runaway.

High performance fluorinated Bismaleimide-Triazine resin with excellent dielectric properties

A series of high performance fluorinated bismaleimide-triazine (BT) resins were prepared from 2, 2′-Bis(4-cyanatophenyl) propane (CY-1), 2′-Bis[4-(4-maleimidephenoxy) phenyl] hexafluoropropane (6FBMP) and diallyl hexafluorobisphenol A (6FDABPA). The effect of the fluorinated groups on the curing behavior, thermal stability, mechanical and dielectric properties was studied. Dielectric constant of the fluorinated BT resin was 2.89–2.94 and the dielectric loss could reach 0.002–0.004 at 1 MHz, which were dramatically improved compared with the reported cyanate ester resins. The fluorinated BT resins also exhibited excellent thermal stability, with a high glass transition temperature above 220 °C and 5% weight loss thermal decomposition temperature (Td5) exceeding 400 °C. Meanwhile, the impact strength of the fluorinated BT resins could reach 20 kJ/m2 and the flexural strength was 120 MPa. Small dipole, low polarizability, high bond energy of the carbon-fluorine (C-F) bond and symmetrical hexafluoroisopropyl group were the reason for the enhanced properties. This work suggested that the fluorinated BT resins had great potential to be used as the matrix of the advanced structural and functional composites.

Thermally stabilized bismaleimide–triazine resin composites for 10-GHz level high-frequency application

A hybrid cured resin with excellent dielectric and thermal properties was prepared with bismaleimide–triazine (BT) resin modified with 2,2′-diallylbisphenol A (DBA). The thermal and dielectric properties of the resin were investigated, and the effect of DBA concentration on the curing reaction was determined. Results indicated that DBA significantly influenced the curing reaction and the properties of the cured product. The modified BT resins exhibited outstanding thermal stability (initial decomposition temperature was over 400°C), although the stability was slightly lower than that of pure BT resins. The dielectric constant and dielectric loss of the cured resin decreased when DBA was introduced into the BT resins. Moreover, the fabricated resins showed dielectric constant of 2.91–3.07 and dielectric loss lower than 0.0057 under the testing high-frequency range of 1 GHz to 15 GHz. Overall, the BT resins modified by DBA display great potential to be applied in high frequency field.

Investigation of structure property relationships in liquid processible, solvent free, thermally stable bismaleimide-triazine (BT) resins

Three cyanate ester monomer or oligomer species: 2,2-bis(4-cyanatophenyl)propane 1, 1-1-bis(4-cyanatophenyl)ethane (2), and the oligomeric phenolic cyanate (Primaset™ PT30) (3), are blended in various ratios with bis(4-maleimidophenyl)methane, (4), to form binary and ternary mixtures (11 in total) and cured, in the absence of catalysts (3Kmin−1 to 150°C+1h; 3Kmin−1 to 200°C+3h), followed by a post cure (3Kmin−1 to 260°C+1h). The use of liquid monomer, (2), offers the possibility of liquid processing in blends containing minority compositions of bismaleimide. Glycidylmethacrylate is explored as a reactive diluent (2.5–10wt%) to linked interpenetrating network polymer structures comprising cyanate ester and bismaleimide components with glass transition temperatures of 267–275°C, depending on composition; the onset of thermo-oxidative degradation ranges from 386 to 397°C. When a binary blend of (2) and (3) (with the former in the minority) is co-cured with (4), an excellent balance of properties is achieved with liquid processing, a Tg >400°C and onset of degradation of 425°C in static air. Kinetic analysis of DSC data using Ozawa and Kissinger methods yield activation energies of between 107 and 112kJ/mol for a binary blend of (1)90-(4)10, which is in good agreement with literature. Molecular dynamics simulation of the same blend in cured form gave a simulated glass transition temperature of 250°C that is in very close agreement with empirical DMTA data.

High glass transition temperature bismaleimide‐triazine resins based on soluble amorphous bismaleimide monomer

ABSTRACTA novel bismaleimide (DOPO‐BMI) with unsymmetrical chemical structure and DOPO pendant group has been prepared. The particular molecular structure makes DOPO‐BMI show an intrinsic amorphous state with a Tg about 135°C and excellent solubility in most organic solvents, which is beneficial to the processability of bismaleimide composite materials. A series of bismaleimide‐triazine (BT) resins have been prepared based on DOPO‐BMI and 2,2‐bis(4‐cyanatophenyl)propane at various weight ratios. The prepared BT resins show outstanding solubility in organic solvent and low viscosity about 10–671 mPa s at 180°C. The cured BT resins exhibit high glass transition temperature (Tg) over 316°C. As the weight ratio of DOPO‐BMI increases to 80% (BT80), the Tg can rise to 369°C (tan δ). The cured BT resins also show good thermal stability with the 5% weight loss temperature over 400°C under both nitrogen and air atmosphere. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42882.

Microwave curing bismaleimide-triazine composites filled with micro-silica and nano-silica

A novel composite of bismaleimide-triazine (BT) resins containing 2,2′-diallyl bisphenol A (DABPA) and filled with the mixture of micro- and nano-silica particles were cured by conventional thermal and microwave-assisted process. The dielectric and mechanical properties of BT composites were studied in this paper. The results indicated that the curing method, particle size and content of silica had influences on the dielectric and mechanical properties of BT composites. The dielectric constant and dielectric loss tangent of microwave-cured samples were lower than those of the thermal cured samples because of the different curing mechanism. With the increase of micro-silica content, the dielectric constant of BT composites increased, while the dielectric loss tangent decreased. Due to the decrease of the free volume, the dielectric constant and dielectric loss tangent decreased when the nano-silica particles were incorporated into the composites. In addition, the flexural strength of the BT composites will also be improved by incorporating appropriate amount of micro- and nano-silica particles.

Effect of functionalized multiwall carbon nanotubes on the curing kinetics and reaction mechanism of bismaleimide–triazine

Functionalized multiwall carbon nanotubes (f-MWCNTs) with varying functionalization degrees were prepared by chemical methods. The effect of f-MWCNTs on the cure kinetics of bismaleimide–triazine (BT) resin was studied through nonisothermal differential scanning calorimetry (DSC) methods. The reaction activation energy (Eα) was determined by Flynn–Wall–Ozawa method. The results show that f-MWCNTs have more acceleration ability than pristine MWCNTs, due to more groups on the surface of f-MWCNTs than that of pristine MWCNTs. The activation energy was decreased from a value of 91.3 kJ mol−1 for the neat BT resin to 74.2 kJ mol−1 at the small mass loading (1.0 %) of f7-MWCNTs. The effect of f-MWCNTs on the reaction mechanism has been investigated. It shows that the f-MWCNTs accelerate the cure reaction of BT resin by providing the Lewis acids (H+) to make the “Diels–Alder” reaction and “ENE” reaction of BT resins more efficient. These findings offer useful insights into the cure technology of thermosetting resin filled with f-MWCNTs, without negative effect on the cure reaction.

Dielectric and thermal properties of polymer network based on bismaleimide resin and cyanate ester containing dicyclopentadiene or dipentene. III

AbstractA series of bismaleimide‐triazine (BT) resins were prepared from commercial bismaleimide (DDMBMI) and 2,6‐dimethylphenol‐dicyclopentadiene dicyanate ester (DCPDCY) or 2,6‐dimethylphenol‐dipentene dicyanate ester (DPCY). The thermal properties of cured BT resins containing DCPD or DP were studied using a dielectric analyzer (DEA), dynamic mechanical analyzer (DMA), and thermal gravimetric analyzer (TGA). These data were compared with that of DDMBMI cured with bisphenol A dicyanate ester (BADCY). The cured DDMBMI/DCPDCY or DDMBMI/DPCY exhibits a lower dielectric constant, dissipation factor, and moisture absorption than those of DDMBMI/BADCY. The effects of blend composition on the glass transition temperatures and thermal stability are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1942–1951, 2007

Dielectric and thermal properties of dicyclopentadiene containing bismaleimide and cyanate ester. Part IV

A novel bismaleimide (BMI), bis(4-maleimidophenoxy-3,5-dimethylphenyl)dicyclopentadiene (DCPDBMI), containing a large dicyclopentadiene (DCPD) and aryl ether linkage, was synthesized from bis(4-aminophenoxy-3,5-dimethylphenyl)dicyclopentadiene and maleic anhydride by the usual two-step procedure that included ring-opening addition to give bismaleamic acid, followed by cyclodehydration to bismaleimide. The monomers were characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (NMR), elemental analyses (EA), and mass spectra (MS). A series of bismaleimide-triazine (BT) resins were prepared from synthesized bismaleimide (DCPDBMI) and then cured with 2,6-dimethyl phenol-dicyclopentadiene dicyanate ester (DCPDCY) at various molar ratios. Thermal properties of cured BT resins (DCPDBMI/DCPDCY) were studied using dielectric analyzer (DEA), dynamic mechanical analyzer (DMA) and thermalgravimetric analyzer (TGA). These data were compared with that of commercial bismaleimide (DDMBMI) cured with bisphenol A dicyanate ester (BADCY). The cured DCPDBMI/DCPDCY exhibits lower dielectric constant, dissipation factor and moisture absorption than those of DDMBMI/BADCY. The effects of blend composition on the glass transition temperatures and thermal stability are discussed.

Thermal behavior and properties of naphthalene containing bismaleimide-triazine resins

A series of bismaleimid·triazine (BT) resins were prepared from various dicyanate esters and 2,7-bis(4-maleimidophenoxy)naphthalene (BMPN), which contains a naphthalene group and an aryl ether linkage in the backbone. Their curing behaviors were characterized by differential scanning calorimetry. The exotherm temperature and polymerization reactivity were strongly affected by the chemical structure of the various dicyanate ester monomer. Thermal behaviors were investigated by thermogravimetric analyses and dynamic mechanical analyses. The glass transition temperatures (Tg) of these cured resins with bismaleimide/dicyanate ester at the 1/2 molar ratio were in the range of 250–322°C, and exhibited excellent thermal stability up to 400°C in nitrogen. These results provided a structure–properties relationship for the cured bismaleimid·triazine resins. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1199–1207, 1998