Morphology and Thermal Stability of Novolac Phenolic Resin/Clay Nanocomposites Prepared via Solution High-Shear Mixing

Phenolic resin/clay composites were prepared by high-shear mixing of clay suspended in CH3OH solutions of Novolac resin and curing agent. Pure clay Cloisite Na+ and pillared clays Cloisite 10A, 30B, and Na(+)Cloisite that was pillared by 3-hexadecyl-1-methylimidazolium bromide were studied. After CH3OH evaporation, Novolac was cured at low temperatures. XRD showed that clay gallery d-spacings decreased upon solvent evaporation and partial curing. Slight d-spacing increases were sometimes observed from a partially cured stage to a further cured composite. Na(+)Cloisite gave the highest nanodispersion, Cloisites 10A and 30B the lowest. TGA revealed that Na+ clay or organoclay incorporation in partially cured and cured composites did not improve the thermal stability of Novolac.