Synthesis of Poly(Isobutylene-B-Epsilon-Caprolactone) Diblock Copolymer Using Enzyme Catalysis
The synthesis of poly(isobutylene-b-ε-caprolactone) block copolymers containing amorphous rubbery/crystalline block segments was accomplished by the combination of living cationic polymerization of isobutylene (IB) with the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The synthesis involved the living cationic polymerization of IB using 1,2-propylene oxide/TiCl4 initiating system and termination with allyltrimethylsilane to yield functionalized allyl-PIB-OH with a Mn=4,306 g/mol and Mw/Mn=1.21. The structure of hydroxyl end-functional PIB was confirmed by 1H NMR and the molecular weight was determined by SEC. The resulting allyl-PIB-OH was successfully used as macroinitiator for the ROP of ε-CL in the presence of Candida Antarctica Lipase B (CALB), giving poly(IB-b-ε-CL) copolymer. The block copolymer exhibited Mn= 7,253 g/mol and Mw/Mn=1.26. Characterization of the block copolymer by SEC, 1H and 13C NMR spectroscopy was performed.
Abstracts of Papers of the American Chemical Society
Castano, Marcelo; Albarran, Alejandra Alvarez; Becker, Matthew; and Puskas, Judit D., "Synthesis of Poly(Isobutylene-B-Epsilon-Caprolactone) Diblock Copolymer Using Enzyme Catalysis" (2004). Polymer Science Faculty Research. 816.