Curing behaviors and properties of epoxy and self-catalyzed phthalonitrile with improved processability

Abstract

The curing behaviors for high-performance resin system phthalonitrile-containing benzoxazine and epoxy (BA-Ph/EP), particularly the effect of the binary system composition and processing conditions on their processabilities were investigated and discussed in this article. Results indicated that all BA-Ph/EP prepolymers exhibited low initial processing viscosity (<0.3 Pa s) and have kept stable low viscosity until gel transition. The suitable molding temperature (ranged from 150°C to 180°C) and molding time (ranged from 20 min to 80 min) could be selected for practical applications of BA-Ph/EP systems. The studies of curing behaviors and gelatinization for BA-Ph/EP systems give further understanding of the curing kinetics and guidance for the fabrication of high-performance copolymers/polymers. The introduction of EP could significantly improve the cross-linking density of BA-Ph/EP polymers, and the appropriate content of EP is the key fact for the improvement. In addition, the effects of postcuring conditions on thermal properties and the adhesive property of BA-Ph/EP polymers were monitored. The thermal stabilities and adhesive property of various polymers also showed an obvious influence with the introduction of EP. The systematic study of BA-Ph/EP system could enable a broadened industrial application, especially in the areas that require high-temperature resistance.

Reactive diluent strategy for general benzoxazine to achieve high performance thermoset via a combination of styrene and glycidyl methacrylate

“…The benzoxazine solution in St is transparent but excessing benzoxazine makes the solution gelatinous, and even lost fluidity (Figures S2 and S3). As shown in Figure S3, the viscosity of the solution increased exponentially with increasing PH‐ddm dissolved, but the viscosity is significantly lower than that of the benzoxazine/epoxy mixture (40 mPa s) at 180°C, which was reported previously 50 …”

“…Therefore, it should be no surprise that the strategy was transferred into the benzoxazine field. Actually, there have been a considerable number of works explored copolymerization of benzoxazine with liquid epoxides, but a minority reported flowability of the mixtures 25,46–50 . Moreover, low viscosity and long storage capability of the mixtures at room temperature are rarely achieved.…”

Development of highly performant hybrid materials based on phthalonitrile resin for a simultaneous ballistic and nuclear shielding protection

“…At the same time, the peak around 1385 cm −1 , linked to the formation of triazine ring, increased in intensity. 26,35,36 This implies that the polymerization reaction has taken place well and therefore the PN curing leads, majorly, to the formation of triazine ring.…”

Properties of high-temperature epoxy/DDS resin systems for bonding application

“…This was due to the increase in viscosities of the systems, which reduced the probability of collision between reactive groups, thereby reducing the rate of curing reaction. 25…”