Methacrylate-terminated polyisobutylenes (PIB-MAs) were synthesized by trans esterification of vinyl methacrylate by hydroxyl-terminated polyisobutylenes (PIB-OH) using Candida antarctica lipase B (Novozyme 435) catalyst in hexane at 50 degrees C. PIB-CH2-CH2-CH2-OH and Glissopal-OH, synthesized by anti-Markovnikov hydrobromination of allyl-terminated PIB and Glissopal (R) 2300 followed by hydrolysis, were quantitatively converted into the corresponding PIB-MAs. H-1 and C-13 NMR spectroscopy verified the formation of the expected structures. This "green" chemistry is a very promising methodology for polymer functionalization in general, and biomaterial synthesis in particular.