Suesuwan Arunthip, Suetrong Natapol, Yaemphutchong Sila, Tiewlamsam Inthikan, Chansaenpak Kantapat, Wannapaiboon Suttipong, Chuanopparat Nutthawat, Srathongsian Ladda, Kanjanaboos Pongsakorn, Chanthaset Nalinthip, Wattanathana Worawat
Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Ladyao, Chatuchak, Bangkok 10900, Thailand.
Concord College, Acton Burnell Hall, Acton Burnell, Shrewsbury, Shropshire SY5 7PF, UK.
Polymers (Basel). 2024 Jun 21;16(13):1767. doi: 10.3390/polym16131767.
In this work, four thymol-based benzoxazines were synthesized using four primary amines with different chain lengths, namely methylamine, ethylamine, 1-propylamine, and 1-butylamine, which are then named T-m, T-e, T-p, and T-b, respectively. The optical properties of the synthesized thymol-based benzoxazines were examined via the photoluminescent study of their solutions in acetone. The results show that all the prepared benzoxazines emitted blue light with the maximum wavelengths from 425 to 450 nm when irradiated by the excitation wavelengths from 275 to 315 nm. The maximum excitation wavelengths are found to be 275 nm. The polymerization of the thymol-based benzoxazines is triggered by heat treatments with different conditions (160, 180, and 200 °C for 1 h). According to the FTIR results, the heat-curing process introduces a presence of the OH peak, of which intensity increases as the curing temperature increases. Thermal decompositions of thymol-based benzoxazines regarding TGA analyses reveal the enhancement of thermal stability of the benzoxazines with respect to the -substituent chain length, as significantly observed the change in the first thermal decomposition at temperature ranged from 253 to 260 °C. Synthesized benzoxazine derivatives are further employed to coat the substrate, e.g., the glass slides. The investigation of the water contact angle shows that the coating of the benzoxazines onto the surface improves the hydrophobicity of the substrate, resulting in the enlargement of the contact angle from 25.5° to 93.3°. Moreover, the anticorrosion performance of the polybenzoxazine coatings is examined using potentiodynamic polarization techniques. The results illustrate the anticorrosion efficiency of the thymol-based polybenzoxazine up to 99.99%. Both hydrophobic and electrochemical studies suggest the feasibility for employing benzoxazines in anticorrosion coating applications.
在本研究中，使用四种不同链长的伯胺，即甲胺、乙胺、1-丙胺和1-丁胺，合成了四种百里酚基苯并恶嗪，随后分别将其命名为T-m、T-e、T-p和T-b。通过对其在丙酮溶液中的光致发光研究，考察了合成的百里酚基苯并恶嗪的光学性质。结果表明，当用275至315nm的激发波长照射时，所有制备的苯并恶嗪均发出蓝光，最大波长为425至450nm。发现最大激发波长为275nm。通过不同条件（160、180和200℃，1小时）的热处理引发百里酚基苯并恶嗪的聚合反应。根据傅里叶变换红外光谱（FTIR）结果，热固化过程引入了OH峰，其强度随着固化温度的升高而增加。关于热重分析（TGA）的百里酚基苯并恶嗪的热分解揭示了苯并恶嗪相对于取代基链长的热稳定性增强，在253至260℃的温度范围内首次热分解的变化显著可见。合成的苯并恶嗪衍生物进一步用于涂覆基材，例如载玻片。水接触角的研究表明，将苯并恶嗪涂覆在表面上可改善基材的疏水性，导致接触角从25.5°增大到93.3°。此外，使用动电位极化技术考察了聚苯并恶嗪涂层的防腐性能。结果表明，百里酚基聚苯并恶嗪的防腐效率高达99.99%。疏水和电化学研究均表明在防腐涂层应用中使用苯并恶嗪是可行的。
