title: Application of Fourier transform infrared (FT-IR) spectroscopy to the study of the modification of epoxidized sunflower oil by acrylation.
abstract: Commercial sunflower oil was epoxidized at the laboratory-scale. The epoxidized sunflower oil (ESFO) was modified following the acrylation reaction. Modification was carried out simultaneously using acrylic acid (AA) and triethylamine (TEA). To optimize the reaction conditions, the  effects of four temperatures (40, 60, 80, and 100 °C), the ESFO:AA (100:100) ratio, and 0.2% TEA were investigated. The rate of conversion was analyzed with both FT-IR and titration of the oxirane ring. After that, the temperature with the highest conversion was selected and used throughout  for all modification reactions. Then, four ratios (100:100, 100:90, 100:80, and 100:75) of ESFO:AA were analyzed at four different concentrations of TEA (0.2, 0.3, 0.4, and 0.5%) to determine the best estimate for both the ESFO:AA ratio and the catalyst concentration. Conversion rate was analyzed  using FT-IR spectroscopy by measuring the concentrations of ester, carbonyl, and alcohol groups. Moreover, oxirane-ring concentration was estimated using the titration method (with gentian violet as indicator) and FT-IR spectroscopy (epoxy ring absorptions at 1270 cm(-1) and  877 cm(-1)). Based on conversion yield, the optimum ESFO:AA ratio corresponds to 100:80; the best temperature reaction was at 60 °C, and the best TEA concentration was 0.2%. The critical amounts of reactants needed to reach maximum conversion were established. The final  acid value of the acrylated ESFO after washing (pH = 7) was 2.1 mg potassium hydroxide (KOH)·g(-1). All results show that FT-IR spectroscopy is a simple, low-cost, rapid method for investigating the kinetics of a reaction.
authors.affiliation: Laboratoire des Sciences et Techniques de l'Environnement, Ecole Nationale Polytechnique, BP 182, El-Harrach, Alger, Algeria.
authors.forename: Ratiba
authors.initials: R
authors.lastname: Irinislimane
authors.forename: Naima
authors.initials: N
authors.lastname: Belhaneche-Bensemra
mesh_terms: D000042:Absorption; D000179:Acrylates / Q000737:chemistry; D001669:Biochemical Phenomena; D004852:Epoxy Compounds / Q000737:chemistry*; D005027:Ethylene Oxide / Q000737:chemistry; D010938:Plant Oils / Q000032:analysis* / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D000074242:Sunflower Oil; D013696:Temperature; D014783:Viscosity
chemical_list: D000179:Acrylates; D004852:Epoxy Compounds; D010938:Plant Oils; D000074242:Sunflower Oil; D005027:Ethylene Oxide