Configurational double bond selectivity in the epoxidation of hydroxy‐terminated polybutadiene with m ‐chloroperbenzoic acid

The selectivity of the three different double bonds (CIS, TRANS and VINYL) of hydroxyterminated polybutadiene regarding epoxidation was evaluated, using m ‐chloroperbenzoic acid in toluene below room temperature (−10°C, −5°C, 0°C and 5°C). To determine the kinetic constants for the three configuratons ( k 1,cis = (2,59–0,6) × 10 −2 L · mol −1 · min −1 ; k 2, trans = (5,35–0,82) × 10 −2 L · mol −1 · min −1 ; k 3, vinyl = (0,97–0,01) × 10 −2 L · mol −1 min −1 ), 1 H and 13 C NMR was used along with a system of three parallel equations. The activation energy values were also evaluated ( E a, cis = 53,9 kJ · mol −1 ; E a, trans = 70,7 kJ · mol −1 and E a , vinyl = 261,1 kJ · mol −1 ) for the three double bond types.