The radical telomerization of 1,3-butadiene in the presence of 1-iodoperfluorohexane and 1-iodoperfluorooctane (RFI) is presented. Experimental parameters (such as the nature of the radical initiator, temperature, solvent and initial molar ratios of the reactants) were varied to increase both 1,3-butadiene and RFI conversions. Best conditions are reached at 140-150 degrees C with di-tert-butyl peroxide as initiator and acetonitrile as solvent. According to different conditions, the monoadduct and higher order telomers were synthesized with average number molecular weights ranging from 250 to 4000 as determined by H-1 NMR spectroscopy and elemental analysis. 80 of the 1,4-adducts were noted to lack a terminal iodine atom. The transfer constant of RFI towards 1,3-butadiene was determined to be C-T = 2.59 at 145 degrees C which induces the formation of nonfunctional oligomers when a high butadiene(0)/RFI(0) molar ratio was used. References: 25
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