Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

Guohu Zhang; Ahmed F M El-Mahdy; Lamiaa Reda Ahmed; Babasaheb M Matsagar; Sameerah Al-Saeedi; Shiao-Wei Kuo; Kevin C-W Wu

doi:10.3390/polym14030449

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

Polymers (Basel). 2022 Jan 23;14(3):449. doi: 10.3390/polym14030449.

Authors

Guohu Zhang¹, Ahmed F M El-Mahdy¹, Lamiaa Reda Ahmed^{1

2}, Babasaheb M Matsagar³, Sameerah Al-Saeedi⁴, Shiao-Wei Kuo^{1

5}, Kevin C-W Wu^{3

6}

Affiliations

¹ Center for Functional Polymers and Supramolecular Materials, Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
² Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
³ Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
⁴ Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia.
⁵ Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
⁶ International Graduate Program of Molecular Science and Technology, National Taiwan University (NTU-MST), No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.

Abstract

New porphyrin-functionalized benzoxazine (Por-BZ) in high purity and yield was synthesized in this study based on ¹H and ¹³C 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 CH₂O. 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.

Keywords: metal complex; polybenzoxazine; porphyrin; ring-opening polymerization; thermal stability.

Grants and funding

109-2221-E-110-067-MY3/MOST