In Situ Monitoring of the Reaction-Induced Self-Assembly of Phenolic Resin Templated by Diblock Copolymers

In this study,in situ small-angle X-ray scattering (SAXS), in situ Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM) are used to monitor the formation of ordered mesophases in cured mixtures of phenolic resin and the diblock copolymer poly(ethylene oxide-block-epsilon-caprolactone) (PEO-b-PCL). SAXS and TEM analyses reveal that the mesophase of the phenolic/PEO-b-PCL mixture transforms sequentially from disordered to short-range-ordered to hexagonal-cylindrical to gyroidal during the curing process when using hexamethylenetetramine (HMTA) as a cross-linking agent, indicating that a mechanism involving reaction-induced microphase separation controls the self-assembly of the phenolic resin. In situ SAXS is also used to observe the fabrication of mesoporous phenolic resins during subsequent calcination processes.