Surface Chemistry Effects on the Reactivity and Properties of Nanoconfined Bisphenol M Dicyanate Ester in Controlled Pore Glass

The influence of nanoconfinement on the cure kinetics and glass transition temperature of a bisphenol M dicyanate ester/polycyanurate material is investigated as a function of surface chemistry and nanoconfinement size in controlled pore glass (CPG). The glass transition temperature and conversion as a function of cure time is investigated using differential scanning calorimetry. The native CPG surface accelerates the cure of bisphenol M dicyanate to a larger extent compared to the silanized hydrophobic CPG presumably because of the catalytic nature of surface hydroxyl groups of the native pores. Two T$_{g}$s are observed for both monomer and polycyanurates confined in the native CPGs. For the fully cured polycyanurate, the primary T$_{g}$ is depressed by 60 K at 11.5 nm, and the secondary T$_{g}$ is 10 to 33 K above the primary T$_{g}$. The length scale associated with the secondary T$_{g}$ is approximately 0.8 nm. Based on the measurements of both T$_{g}$ and sol content as a function of conversion, the network structure does not change upon nanoconfinement.