POLYMERIZATION OF OXEPAN-2,7-DIONE IN SOLUTION AND SYNTHESIS OF BLOCK COPOLYMERS OF OXEPAN-2,7-DIONE AND 2-OXEPANONE

The ring-opening polymerization of oxepan-2,7-dione was initiated with 1) cationic initiators such as AlCl3 and BF3.(C2H5)2O, 2) anionic initiators such as CH3COO-K+ and NaH, and 3) coordination-type initiators such as stannous 2-ethylhexanoate and dibutyltin-type initiators such as stannous 2-ethylhexanoate and dibutyltin oxide. The reactions were studied at 0, 20, and 40-degrees-C in methylene chloride. Oxepan-2,7-dione was also reacted with epsilon-caprolactone (2-oxepanone) in the presence of aluminum isopropoxide as a catalyst to generate A-B block copolymers.