Akademik Veri Yönetim Sistemi
JOURNAL OF FOOD ENGINEERING, 2025 (SCI-Expanded)
This study presents an experimental setup to evaluate in situ changes in the corrosion protection performance of food can coatings under retort conditions (121 degrees C for 90 min; 204,774 Pa). Bisphenol A (BPA)-based epoxy phenolic coating is compared to non-BPA polyester phenolic coatings. Non-BPA coatings were formulated with three levels of phenolic crosslinker to control the glass transition temperature (Tg). Coated tinplate was exposed to 1% NaCl solution and monitored before, during, and after retorting using electrochemical impedance spectroscopy (EIS). Charge-transfer resistance (Rct), pore resistance (Rpore), and coating capacitance (Cc) from equivalent circuit modeling of impedance data served as quantitative metrics for coating performance and mapped to Tg. There were no clear trends in coating performance correlated with polymer properties before retorting. During retorting, however, Rpore increased with Tg such that coatings could better resist the migration of corrosive species. This strong positive correlation between Rpore and Tg was also observed after 28 d of storage in 1% NaCl solution at 50 degrees C post-retorting, suggesting potential service life prediction capability. In situ EIS measurements during retorting could serve as a useful tool to screen coating formulations to accelerate the design and development of novel non-BPA coatings.