<p>Porphyrins added to alkyd resins can be a way to enhance these organic coatings through a physical barrier, in order to reduce permeability, decrease porosity, and improve film adhesion. This helps prevent oxygen and ions from acting on metal structures, thereby extending their lifespan. This work aimed at the synthesis and characterization (UV–vis, FT-IR, <sup>1</sup>H and <sup>13</sup>C NMR, TGA) of a <i>meso</i>-porphyrin and its zinc metalated analogue derived from cardanol, the main constituent of Cashew Nut Shell Liquid (CNSL), and Vanillin, a molecule obtained from lignin. The goal was to incorporate these products into alkyd resins for use as anticorrosive agents, evaluating them through electrochemical studies, adhesion, gloss, hardness, and solvent resistance. The results of electrochemical impedance spectroscopy showed that the alkyd resin containing the zinc-metalated <i>meso</i>-porphyrin (Zn-PCV/Ak) exhibited higher impedance modulus values (|Z|<sub>0,06&#xa0;Hz</sub> greater than 10<sup>9</sup> Ω·cm<sup>2</sup>), as well as increased solvent resistance, compared to pure alkyd resin (blank) (|Z|<sub>0,06&#xa0;Hz</sub> close to 10<sup>9</sup> Ω·cm<sup>2</sup>) or alkyd resin with metal-free <i>meso</i>-porphyrin added (PCV/Ak) (|Z|<sub>0,06&#xa0;Hz</sub> value lower than 10<sup>8</sup> Ω·cm2). This latter may compromise protection due to strong coordination with transition metals, such as iron present in the metal plates. This indicates the potential use of <i>meso</i>-metalloporphyrin (Zn-PCV) as an additive for anticorrosive protection.</p> Graphical Abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Innovative approach to corrosion protection using cardanol and vanillin porphyrins in alkyd resins

  • Malena Gomes Martins,
  • Lucas Renan Rocha da Silva,
  • Paulo Vitor Macedo da Silva,
  • Rafaelly Nascimento Araújo,
  • Vitória de Paula Santos,
  • Leonardo Mapurunga de Menezes,
  • Otílio B. F. Diógenes,
  • Walney S. Araújo,
  • Claudenilson da Silva Clemente,
  • Giuseppe Mele,
  • Diego Lomonaco,
  • Selma E. Mazzetto

摘要

Porphyrins added to alkyd resins can be a way to enhance these organic coatings through a physical barrier, in order to reduce permeability, decrease porosity, and improve film adhesion. This helps prevent oxygen and ions from acting on metal structures, thereby extending their lifespan. This work aimed at the synthesis and characterization (UV–vis, FT-IR, 1H and 13C NMR, TGA) of a meso-porphyrin and its zinc metalated analogue derived from cardanol, the main constituent of Cashew Nut Shell Liquid (CNSL), and Vanillin, a molecule obtained from lignin. The goal was to incorporate these products into alkyd resins for use as anticorrosive agents, evaluating them through electrochemical studies, adhesion, gloss, hardness, and solvent resistance. The results of electrochemical impedance spectroscopy showed that the alkyd resin containing the zinc-metalated meso-porphyrin (Zn-PCV/Ak) exhibited higher impedance modulus values (|Z|0,06 Hz greater than 109 Ω·cm2), as well as increased solvent resistance, compared to pure alkyd resin (blank) (|Z|0,06 Hz close to 109 Ω·cm2) or alkyd resin with metal-free meso-porphyrin added (PCV/Ak) (|Z|0,06 Hz value lower than 108 Ω·cm2). This latter may compromise protection due to strong coordination with transition metals, such as iron present in the metal plates. This indicates the potential use of meso-metalloporphyrin (Zn-PCV) as an additive for anticorrosive protection.

Graphical Abstract