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In this work, a bio-based benzoxazine monomer (C-s) is synthesized from cardanol, stearylamine, and paraformaldehyde through solvent-free method. Pyrogallol is used as a curing catalyst for the ring-opening polymerization of benzoxazine. Differential scanning calorimeter (DSC) results reveal that doping with pyrogallol reduces the exothermic peak temperature (T p ) of C-s from 256 to 174 °C. The polybenzoxazine/pyrogallol/polyhedral oligomeric silsesquioxane (PC-s/py/POSS) nanocomposites are prepared via thermal curing. The doping of aminopropyl isobutyl POSS (POSS-NH 2 ) can reduce the dielectric constant of polybenzoxazine. The dielectric constant of PC-s/py/POSS is 2.64 at 1 MHz when the doping amount of POSS-NH 2 is 10 wt%. The results of thermogravimetric analysis (TGA) and water absorption test indicate that the PC-s/py/POSS nanocomposites possess good thermal stability and water resistance. In summary, the PC-s/py/POSS nanocomposites with low curing temperature and low dielectric constant are expected to be applied to the low dielectric materials for microelectronic applications.

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In the recovery of aluminum from coal fly ash, the phase equilibria of solid−liquid systems are important for purifying the aluminum salts. This research investigated phase equilibria of the ternary systems AlCl 3 + CaCl 2 + H 2 O, AlCl 3 + FeCl 3 + H 2 O, and FeCl 3 + CaCl 2 + H 2 O at 298.15 K using isothermal dissolution method. The corresponding phase diagrams and density diagrams were plotted. Both AlCl 3 + CaCl 2 + H 2 O and AlCl 3 + FeCl 3 + H 2 O systems had one invariant point, two univariate curves, two crystallization regions, and no double salts. The FeCl 3 + CaCl 2 + H 2 O system had two invariant points, three crystallization regions and a double salt (CaCl 2 •2FeCl 3 •8H 2 O) that formed at 298.15 K. There is no solid solution in all the three systems.