SYNTHESIS AND CHARACTERIZATION OF AMINO-TERMINATED TELECHELIC POLYBUTADIENE

Butadiene was polymerized with water-soluble 4,4'-azobis(amidinopropan e)dihydrochloride initiator in an ethanol-water medium at 60 degrees C . Important variables, such as the initiator concentration, monomer co ncentration, solvency, and polymerization time and temperature were st udied. C-13-NMR studies showed that no observable chain transfer to et hanol occurred during the polymerization. The conversion of monomer to polymer was significantly increased while maintaining a relatively na rrow molecular weight distribution by intermittent feed of the initiat or. The amidino end-groups of the polymer were transformed into amino groups by reduction using lithium aluminum hydride in THF, so that ami ne-terminated polybutadiene was obtained. The amino functionality of t he polybutadiene was determined by titration to be 2.0. (C) 1995 John Wiley and Sons, Inc.