Resin injection repair is a common method to repair delamination damage in polymer matrixcomposites (PMCs). To repair high-temperature PMCs, the resin should have a very low viscosity, yetcure into a compatible adhesive with high temperature stability. Normally, thermosetting polymers withhigh glass transition temperatures (Tg) are made from monomers with high room temperatureviscosities. Among the high temperature resins, such as bismaleimides, polyimides, and cyanate esters,an exception is a unique type of cyanate ester monomer: bisphenol E cyanate ester (BECy, 1,1’-bis(4-cyanatophenyl)ethane), which has an extremely low viscosity of 90-120 cP at room temperature andpolymerizes as a cross-linked thermoset with a high Tg of 274 °C.BECy monomer is cured via an addition trimerization reaction, without volatile products, to forma high Tg amorphous network. In this study, the cure kinetics of BECy are investigated by differentialscanning calorimetry (DSC). Both dynamic and isothermal experiments were carried out to obtain thekinetic parameters. The activation energy (Ea) of BECy is calculated as 67 kJ/mol and 69 kJ/mol basedon Kissinger and Flynn-Wall-Ozawa methods, respectively. A Tg vs. conversion diagram was plotted byusing isothermal curing data and the empirical DiBenedetto equation was used to evaluate therelationship between Tg and conversion.
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