Synthesis of Vinyl-Trivinyl Acidic Resins for Application in Catalysis: Statistical Study and Site Accessibility Assessment

This study aimed to synthesize sulfonated polymer resins based on styrene and trimethylolpropane triacrylate (TMPTA) and evaluate their catalytic efficiency in glycerol acetylation. A factorial design was used, with two factors, three levels, and three replicates of the center point. The factors were cross-linker percentage (Y-TMPTA) and cross-linker feed time (T-TMPTA). Ion-exchange capacity, swelling index, and catalytic efficiency were analyzed to characterize each resin. Lower cross-linker percentages resulted in higher catalytic efficiencies, as expected. Resins synthesized with 2, 6, and 10% TMPTA had mean catalytic efficiencies of 215, 176, and 121, respectively. A linear correlation was observed between catalytic efficiency and cross-linker percentage, with R-2 = 0.9971. Statistical and kinetic models were developed to represent the experimental results and support the development of strategies to improve resin formulation and synthesis conditions. TMPTA feed time at low and high levels positively influenced catalytic efficiency; the result is attributed to the micro- and macrostructure of resins. This finding was corroborated by the kinetic constants provided by the model.