The effect of bismaleimide on thermal, mechanical, and dielectric properties of allyl-functional bisphthalonitrile/bismaleimide system

Abstract

Allyl-functional phthalonitrile (DBPA-Ph) and bismaleimide (BMI) have been considered as advanced composite-matrix resins applied in various fields. In this work, self-promoted polymerization behavior and processability of DBPA-Ph/BMI system were investigated in detail. To further reveal the effect of BMI on the properties of DBPA-Ph/BMI system, the blends and the prepolymers of DBPA-Ph/BMI were prepared in different proportions. Their curing and rheological behaviors were investigated by differential scanning calorimetry and dynamic rheological analysis. The results further confirmed the possible reaction mechanisms and demonstrated that DBPA-Ph/BMI prepolymers exhibited good processability, which included wide processing window (approximately 75°C), low melting viscosity (<0.2 Pa·s), and better reactivity. The copolymers exhibited satisfactory thermal stabilities ( T5% > 421°C, char yield at 600°C >70%). Moreover, the DBPA-Ph/BMI/glass fiber composite laminates were prepared and the effect of the curing temperature and BMI content on mechanical properties and dielectric properties were also investigated. The results show that the composite laminates exhibit favorable mechanical properties and weak frequency dependence of dielectric properties over a wide frequency range. Above all, the research on DBPA-Ph/BMI system could expand its applications in industry, especially in the areas, which require high temperature resistance and excellent mechanical and dielectric properties.

Synthesis and properties of a novel high-temperature vinylpyridine-based phthalonitrile polymer

“…Phthalonitrile resins are a class of heat-resistant thermosetting materials and known for their remarkable properties. [1][2][3][4][5][6][7] The distinguished comprehensive performance of these materials is beneficial for widespread applications, including microelectronic packing, 8,9 aerospace, 10 adhesives, 11 radiation shielding, [12][13][14] and advanced composite matrices. [15][16][17][18] Nevertheless, the course of solidifying pure phthalonitriles has been considerably slow.…”

Micromorphology and Mechanical and Dielectric Properties of Bismaleimide Composite Modified by Multiwalled Carbon Nanotubes and Polyethersulfone

“…The reasons were probably that the polarization could completely keep up with the change of the electric field at low frequency, and the absorbed energy could be returned to the electric field in time, so the dielectric loss was smaller. At high frequency, the orientation polarization needed to overcome the internal resistance of the material, while the dipole steering lagged behind the variation of the electric field and the relaxation phenomenon was obvious [29]. When the frequency was adequately high, the orientation polarization needed a long time in the relaxation process, so the variation of the dielectric loss was small at this time.…”

Investigation on curing reaction of phthalonitrile resin with nanosilica and the properties of their glass fiber‐reinforced composites

“…Due to the inherent brittleness of thermosetting resins, pure thermosetting resins were hardly used as structural, substrate, or functional materials. In order to improve the brittleness of thermosetting resins, continuous fiber, nanoparticles were widely applied to reinforce the thermosetting resins to fabricate composites with enhanced properties 1–4 . Compared with that of traditional inorganic metal materials, fiber‐reinforced composites possessed outstanding properties, such as, light weight, high strength and modulus, outstanding corrosion resistance, and easy processing, which were intensively investigated and greatly used in car industry, new‐energy industry, electronics industry, and so on.…”