Calixarene–based cyanate ester resin for high-temperature material

Abstract

p-tert-Butylcalix[4]arene-derived cyanate ester resins, both single and binary systems, were synthesized and studied for their thermal properties. The results showed that pure calixarene cyanate ester can be thermally cured at comparatively high temperature, which remains in original powder state after thermally cured. So the pure calixarene cyanate ester resin fails to meet the processing demands of resin-matrixed composite. In this work, p-tert-butylcalix[4]arene cyanate ester was chemically functionalized to have highly decreased thermal cure temperature (by copolymerization with epoxy, bisphenol A cyanate ester (BPACE), and polysilazane (PSZ), respectively). The binary resins were thermally cured into monolithic materials. The optimal acceleration of thermal cure reaction was achieved with an addition of 10% PSZ. The addition of epoxy resin decreased thermal resistance and carbon yield of p-tert-butylcalix[4]arene cyanate ester and addition of BPACE slightly decreased thermal resistance and carbon yield, while PSZ highly improved thermal resistance and carbon yield. Glass transition temperature of the co-cured resin of calixarene cyanate ester with 10% PSZ was much higher than that of conventional BPACE. Calixarene cyanate ester possesses much better property than that of conventional BPACE resin.

Preparation of hybrid cyanate ester resin in the presence of polysilazane and its properties

“…According to the literature, polysilazane (PSZ) containing amino group is an effective catalyst for the trimerization reaction of cyanate esters, and the thermal stability of the organic resin can be improved by the inorganic polysilazane. 25,26 In our previous work, it was found that the –O–Si–NH–CN structure was formed by attacking the nitrogen atom in PSZ with positive carbon atom (–O–C≡N) in BADCy, and the –O–Si–NH–CN structure can play a catalytic role in cyanate resin. 27 In addition, the –NH–CN groups can react to form a triazine ring structure at a lower temperatures.…”