Synthesis, characterization and adsorption behavior of sinapic acid imprinted polymer via precipitation polymerization

A cost-effective and eco-friendly approach for extraction and clean-up of sinapic acid was developed via the use of molecularly imprinted polymers (MIPs). Acetonitrile/methanol (5:1) was used as the porogenic solvent system, sinapic acid as the template, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent were used to prepare MIPs via precipitation polymerization. A series of MIPs were synthesized with variable template: monomer: cross-linker mole ratios: 1:4:20, 1:8:20 and 1:8:32. Polymers were characterized by complementary methods: scanning electron microscopy (SEM), dynamic light scattering (DLS), gas adsorption analysis, infrared absorption spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The batch rebinding experiments were conducted to evaluate polymer performance in terms of relative binding affinity towards the template. The initial concentration and solution pH strongly affect the binding capacity of polymers in aqueous media. Moreover, the fabricated MIPs were successfully applied for extraction of sinapic acid from rapeseed meal extract.