This paper reports the synthesis and characterization of polyisobutylene disulfides by living reversible recombination radical polymerization (R3P). First telechelic thiol-functionalized PIB macromonomer (HS-PIB-SH) was synthesized using enzyme-catalyzed transesterification. Then the HS PIB SH was chain-extended using hydrogen peroxide, triethylamine catalyst and air to yield polyisobutylene disulfides up to M-n = 96 000 g/mol. 750 MHz HMBC correlation NMR spectroscopy along with Raman spectroscopy showed the absence of SH end groups. Thermal analysis by DSC showed a T-g of -62.5 degrees C and TGA indicated that the polymer began to degrade at 340 degrees C. The increased T-g together with structural and SEC analysis indicate that this R3P likely yields macro cycles. Dithiothreitol (DTT) reduced the polyisobutylene disulfides to a mixture of pentamer-to-dimer PIB-dithiols.