Studies on thermal and dielectric properties of organo clay and octakis (dimethylsiloxypropylglycidylether) silsesquioxane filled polybenzoxazine hybrid nanocomposites

Two types of polybenzoxazine (PBZ) hybrid nanocomposites were prepared from new type of benzoxazine monomer (BZ-Cy-OH) and organo-modified MMT clay (OMMT) and octakis (dimethylsiloxypropylglycidylether) silsesquioxane (OG-POSS) (up to 7.5 wt%). The new BZ-Cy-OH prepared from trans-4-aminocyclohexanol hydrochloride and 37% formaldehyde solution with 1,1-bis (3-methyl-4-hydroxy phenyl) cyclohexane and its structure was conformed by FTIR and NMR (¹H and ¹³C) spectral studies. The thermal properties of the resulting hybrid PBZ nanocomposites were studied by using differential scanning calorimetric and thermogravimetric analysis. Comparative study revealed on the data from the DSC analysis, the newly synthesized BZ-Cy-OH started ring opening polymerization at the lower temperature than that of the conventional benzoxazine (Ba-A). The dispersion of OMMT clay in the PBZ was confirmed by X-ray diffraction analysis. The homogeneous morphology of the hybrid nanocomposites was studied by using scanning electron microscope and transmission electron microscope analysis. By comparing the dielectric properties of organoclay and POSS filled PBZ nanocomposites, it was observed that the POSS filled PBZ showed low dielectic constant and in the case of organoclay filled PBZ possessed high dielectric constant. POLYM. COMPOS.