Synthesis of macroazoinitiator by direct polycondensation for block copolymerization of styrene and butadiene

Macroazoinitiator (MAI) was prepared from hydroxy-terminated polybutadiene (HTPB) and 4,4 ' -azobis-4-cyanopentanoic acid (ACPA) by direct polycondens ation in the presence of 1-methyl-2-chloropyridinium iodide (MCPI) at room temperature. This MM proved to be an effective initiator for thermal polyme rization of styrene at 60 degreesC. The resulting products were characteriz ed by viscosity measurements and both IR and NMR spectral studies. The rati o of styrene and butadiene units was calculated from NMR spectral data and scanning electron micrography. (C) 2001 John Wiley & Sons, Inc.