Surface properties and thermal stability of a novel low-surface-energy polybenzoxazine/clay nanocomposites

Abstract

A novel type of polybenzoxazine (PB-m)/clay nanocomposites were prepared from 2-bis (3-methyl-3,4-dihydro-2H-1,3-benzoxazinyl) propane (B-m) and di-methyl, di-octadecyl ammonium chloride (DODMAC)-modified clay. Surface properties and thermal stability of the PB-m/clay nanocomposites were characterized by contact angle measurement and thermogravimetry (TGA), respectively. It was found that the PB-m/clay nanocomposites possess the lowest surface free energy (15.27 mJ/m2) after 8 h curing at 210°C, which is even lower than that of poly (tetrafluoroethylene) (21.0 mJ/m2), and the presence of the clay in the B-m PB-m matrix enhances the stability of the surface energy at 210°C. FTIR results show that the intercalated structures of PB-m/clay nanocomposites have no influence on the hydrogen-bonding network of the PB-m during curing. Combining with the results of atomic force microscope, it can be concluded that the stability of surface energies of the PB-m/clay nanocomposites is mainly affected by the migration and masking of clay. Also, TGA results show that the addition of clay improves the thermal stability of PB-m. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers