Rapid Curing System of a Cyanate Ester Resin/Epoxy Resin with a Thermal Latent Polymeric Hardener Based on a Phenol–Amine Salt

Abstract

We studied the thermal behavior and curing process of a cyanate ester resin (Cy)/epoxy resin (EP)/thermal latent polymeric hardener system based on a phenol–amine salt (PA-hardener) and the resulting cross-linked structure. Additionally, the physical properties of the cured product were evaluated. As a result, the curing system of Cy/EP with the PA-hardener was found to have unique thermal behavior, and an adhesion process was conducted in which the functionality and reactivity of the cyanate ester resin were utilized. The system cured rapidly at approximately 80 °C and could be completely cured at 120 °C in 1 h because the PA-hardener dissolved in the resins at an elevated temperature to give free amines, which could readily initiate the polymerization of cyanate ester resins and epoxy resins. The glass-transition temperature (T g) of the cured products increased with increasing a triazine-rich cross-linked structure derived from the cyclotrimerization of the cyanate ester resin as the curing proceeded at a relatively low temperature. The Cy/EP/PA-hardener system was found to have a rapid curing process and excellent adhesiveness, and it afforded a cured product with heat stability.

Characterization of Environmentally Conditioned Quartz–Cyanate Ester Composites for Radome Applications

“…Resin impregnation was carried out at 640 mmHg vacuum pressure for 4 h. An air-circulating oven was employed for curing (175 ± 5 °C for 10 h) with a heating rate of 1 °C/min until curing temperature was attained. The curing mechanism is illustrated in Figure . , Laminates were allowed to cool naturally to room temperature (Figure ). To retain toughness and dielectric properties, postcuring of these thermoset composite laminates was avoided.…”

“…Curing mechanism of cyanate ester. , Reproduced with permission from ref . Copyright 2000 John Wiley & Sons, Inc.…”

“…The curing mechanism is illustrated in Figure 1. 19,20 Laminates were allowed to cool naturally to room temperature (Figure 2). To retain toughness and dielectric properties, postcuring of these thermoset composite laminates was avoided.…”

High-Performance Reworkable Underfill Adhesives Based on Dicyclopentadiene Epoxy Thermoset

“…Formula F5 also contained 5% of commercially available cyanate ester bisphenol E cyanate ester. Cyanate esters have been known to co-cure well with epoxy resins, and they help lower the viscosity and improve the Tg and modulus of cured networks [20]. The formulations also contain additives such as carbon black color, dispersants, inhibitors, and silane adhesion promoters.…”

Cyanate Ester Polymerization: Overview of Mechanistic and Kinetic Aspects

“…[14] Certainly, the most practically important reactions of cyanate esters are the ones leading to the formation of polymeric materials. Cyanate esters can be polymerized, as well as copolymerized with benzoxazines, [15][16][17] bismaleimides, [18][19][20] epoxies, [21][22][23] and DOI: 10.1002/macp.202200384 also can form polymers by a reaction with phenols [24,25] and some conjugated dienes. [26] Cyanate esters polymerization has been reviewed repeatedly.…”