Trifunctional quinoxaline‐based maleimide and its polymer alloys with benzoxazine: Synthesis, characterization, and properties

Abstract

Novel quinoxaline-based trismaleimide (2,3-di[3-maleimido]phenyl-6-maleimidoquinoxaline, namely TQMI) and its polymer alloys with 3-phenyl-3,4dihydro-2H-1,3-benzoxazine (P-a) were successfully prepared and characterized. Differential scanning calorimetry investigation of TQMI exhibited distinct double exothermic peaks, which implied that the curing behavior of different type of maleimide group was discrepant. The curing temperature of P-a/TQMI prepolymers was lower than that of both neat TQMI and P-a monomer. The temperatures at 5% (T 5) and 10% (T 10) weight loss and the char yield (Y c) of cured TQMI at 800 C reached 513 C, 524 C, and 63.5%, respectively, which were much higher than the record of traditional 4,4 0bismaleimideodiphenylmethane (BMDPM) resin as well as most of other reported bismaleimide resins. Moreover, the addition of TQMI enhanced thermal stability, glass transition temperature (T g), and limiting oxygen index of benzoxazine resin dramatically. Attractively, the T g value of P-a/ TQMI copolymer at 30 wt% TQMI loadings was approximately 20 C higher than that of P-a/BMDPM copolymer owing to the bulky quinoxaline group.

All‐aromatic ester‐based thermosets: The effect of crosslinking in the nematic or isotropic state

“…The T d 5% 's and char yields at 600°C in N 2 are representative for conventional bismaleimide thermosets 30 . The typical curing temperature of the maleimides (<250°C), 19 is considerably lower than the decomposition temperatures of all oligomers, suggesting the oligomers are thermal stable and the cure temperature is safe to operate for all oligomers.…”

“…Conventional experimental techniques such as DSC, 36–38 FTIR, 19 and UV‐reflection spectroscopy 39 can be used to characterize the cure of maleimides, with isothermal and non‐isothermal techniques. Studies have shown that curing of maleimide follows first order kinetics with an activation energy of ~100 kJ/mol 40,41 .…”

“…In order to control the M n ′s and enable network formation we terminate the polymer chains with maleimide functionalities. We selected maleimide end‐groups because of their accessible cure window (200–300°C) 17–19 . High molecular weight reference polymers are labeled LC‐ref and AM‐ref.…”

Curing characteristics, kinetics, and thermal properties of multifunctional fluorene benzoxazines containing hydroxyl groups

“…The curing temperature, curing time, curing degree, and curing reaction rate are important parameters in the process of material processing 43 . The curing reaction can be carried out depends on the apparent activation energy of the curing reaction system, and the apparent activation energy directly reflects the degree of difficulty in the polymerization of the resin system 44 . Therefore, the study on the curing power of MB‐FH monomers, the relationship between the curing process and product properties, and the optimization of curing process conditions have attracted extensive attention from the scholars.…”

Modification of traditional benzoxazine by blending with polyfunctional benzoxazines containing aromatic group and fluorene group

“…[10][11][12][13] For improving the performance of benzoxazine resins and expanding their application in the field, a large number of researchers have done a lot of research work on the modification of benzoxazine resin. [17][18][19][20][21][22] It is a very important method in improving the properties of benzoxazine resin by blending or copolymerizing. [23][24][25][26][27][28][29][30] By blending or copolymerizing, the crosslinking density of polybenzoxazine resin can be effectively increased, and the mechanical properties and thermal stability of the polymer can be significantly improved.…”