Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine.
Guohu ZhangAhmed F M El-MahdyLamiaa Reda AhmedBabasaheb M MatsagarSameerah Al-SaeediShiao-Wei KuoKevin C-W WuPublished in: Polymers (2022)
New porphyrin-functionalized benzoxazine (Por-BZ) in high purity and yield was synthesized in this study based on 1 H and 13 C NMR and FTIR spectroscopic analyses through the reduction of Schiff base formed from tetrakis(4-aminophenyl)porphyrin (TAPP) and salicylaldehyde and the subsequent reaction with CH 2 O. Thermal properties of the product formed through ring-opening polymerization (ROP) of Por-BZ were measured using DSC, TGA and FTIR spectroscopy. Because of the rigid structure of the porphyrin moiety appended to the benzoxazine unit, the temperature required for ROP (314 °C) was higher than the typical Pa-type benzoxazine monomer (ca. 260 °C); furthermore, poly(Por-BZ) possessed a high thermal decomposition temperature ( T d10 = 478 °C) and char yield (66 wt%) after thermal polymerization at 240 °C. An investigation of the thermal and luminescence properties of metal-porphyrin complexes revealed that the insertion of Ni and Zn ions decreased the thermal ROP temperatures of the Por-BZ/Ni and Por-BZ/Zn complexes significantly, to 241 and 231 °C, respectively. The metal ions acted as the effective promoter and catalyst for the thermal polymerization of the Por-BZ monomer, and also improved the thermal stabilities after thermal polymerization.