Curing behavior and properties of benzoxazine‐co‐self‐promoted phthalonitrile polymers

Abstract

A new high‐performance copolymer was successfully obtained via concerted catalysis polymerization of mono‐functional benzoxazine (P‐a) and self‐promoted 4‐aminophenoxy phthalonitrile (4‐APN) monomers. The FTIR and DSC curves of the P‐a/4‐APN in different blend ratios suggested that the monomer blends can be completely cured without the addition of curing additive. The P‐a/4‐APN copolymers were cured at relatively lower curing temperatures and time. The TGA curves revealed that the P‐a/4‐APN copolymers have good thermal stability in terms of T5, T10, and char yield. A gradual increase in the glass transition temperature (Tg) values and decline were seen in the storage modulus as the loading of 4‐APN was increased from 10 to 30 wt % in the copolymer. The SEM analyses showed that copolymer's fracture surface is dendritic, showing the stress has been dispersed to a certain extent. The study revealed that the poly(P‐a/4‐APN) copolymer have much better thermal stabilities than the poly(P‐a), and the prepared copolymer can be used as a high‐performance thermosetting resin. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46578.

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

“…This can be ascribed to the prepolymerization of BA‐ph in solution. The ring‐opening reaction of benzoxazine rings generated Mannich bridge, which possessed phenolic hydroxyl group and amine structures could catalyze the ring‐opening of benzoxazine rings and ring‐forming of nitrile groups 25,32 . Thus, the temperature of exothermic peak decreased.…”

“…The ringopening reaction of benzoxazine rings generated Mannich bridge, which possessed phenolic hydroxyl group and amine structures could catalyze the ring-opening of benzoxazine rings and ring-forming of nitrile groups. 25,32 Thus, the temperature of exothermic peak decreased. For CE, due to the presence of phenolic hydroxyl group, curing reaction of OCN groups could be promoted and carried out at lower temperature.…”

Modification of Solventless‐Synthesized Benzoxazine Resin by Phthalonitrile Group: An Effective Approach for Enhancing Thermal Stability of Polybenzoxazines

“…Besides, the performance of the phthalonitrile resins to the gamma rays radiation and shielding resistances has also been confirmed . Similar to phthalonitrile‐containing polymers, benzoxazine resins can also be applied to obtain high‐performance materials . Copolymerization of benzoxazine/phthalonitrile has been studied and the prepared copolymers can be used as high‐performance matrix in various fields .…”

“…Similar to phthalonitrile‐containing polymers, benzoxazine resins can also be applied to obtain high‐performance materials . Copolymerization of benzoxazine/phthalonitrile has been studied and the prepared copolymers can be used as high‐performance matrix in various fields . However, the copolymerization between benzoxazine and phthalonitrile could result in uneven distribution of different phases, which may weaken the mechanical and thermal properties of materials.…”

Enhanced properties of phthalonitrile resins under lower curing temperature via complex curing agent

“…So far, several methods have been developed to improve the above problems, including design of new phthalonitrile resin precursors and curing agents . For example, Yang et al prepared two novel tetrahydrophthalic anhydride end‐capped imide compounds to promote the curing reaction of 1,3‐bis(3,4‐dicyanophenoxy)benzene and also studied the effects of comonomer structure on the curing behavior and thermal performance of phthalonitrile resins.…”