Degradation of the oxirane ring of epoxidized vegetable oils in liquid-liquid systems: II. Reactivity with solvated acetic and peracetic acids
2005; National University of the South; Volume: 35; Issue: 3 Linguagem: Inglês
ISSN
1851-8796
AutoresAlejandrina Campanella, Miguel A. Baltanás,
Tópico(s)Polymer Science and PVC
ResumoThe impact of the main process variables (agitation, pH, temperature, concentration levels) on the degradation of the oxirane ring of epoxidized soybean oil (ESO) by attack by solvated acetic and peracetic acids in two-phase (polar- organic) systems when a homogeneous acid catalyst is used, is analyzed in detail. The first degradation reaction is first order with respect to the epoxide concentration and second order with respect to the solvated acetic acid (kAA(70oC) = 4.27 r 0.12 u 10 -5 l 2 mol -2 min -1 ; EaAA = 12.9 r 0.64 kcal mol -1 ). The degradation increases notoriusly the lower the pH of the reacting media is; the increase is directly proportional to the concentration of protons, as is usually found in homogeneous catalysis (for very low pHs the reaction is almost instantaneous). Likewise, the degradation reaction with peracetic acid is first order with respect to the epoxide (kPAA(70oC) = 4.31 u 10 -4 l
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