Abstract
In part 1, we have developed the complexes that can mediate the polymerization of lactone with stereoselectivity. The bulky group, tert-butyl, was including to the position close to enhance the steric effect, which increased the catalytic activity and stereoselectivity in ring opening polymerization of rac-lactide. BTPIP2-tBuZnEt led to a ring opening polymerization of rac-lactide to 99% monomer conversion in 5 hours at 30oC with PDI equal to 1.05 and Pr = 0.64. In part 2, we synthesized the block copolymer via different mechanisms. First, the styrene was polymerized by living radical polymerization. Second, the polycaprolactone was polymerized by ring opening polymerization. We also used the Cp2Ti Cl2 as catalyst and anisaldehyde as initiator to synthesize the block copolymer of polystyrene and polycaprolactone through chain extension and one-pot recation.