Synthesis and ring-opening polymerization of co-cyclic (aromatic aliphatic disulfide) oligomers

An effective approach was presented for the synthesis of co-cyclic(aromatic aliphatic disulfide) oligomers by catalytic oxidation of aromatic and aliphatic dithiols with oxygen in the presence of a copper-amine catalyst. The aromatic dithiols can be 4,4-oxybis(benzenethiol), 4,4-diphenyl dithiol, 4,4'-diphenylsulfone dithiol. The aliphatic dithiols can be 1,2-ethanedithiol, 2,3-butanedithiol, 1,6-hexane dithiol. The co-cyclic(aromatic aliphatic disulfide) oligomers were characterized by gradient HPLC, MALDI-TOF-MS, GPC,H-1-NMR, TGA, and DSC techniques. The glass transition temperatures of these co-cyclics ranged from -11.3 to 56.6degreesC. In general, these co-cyclic(aromatic aliphatic disulfide) oligomers are soluble in common organic solvents, such as CHCl3, THF, DMF, DMAc. These co-cyclic oligomers readily underwent free radical ring-opening polymerization in the melt at 180degreesC, producing linear, tough and high molecular weight poly(aromatic aliphatic disulfide)s. The glass transition temperatures of these polymers ranged from -3.7 to 107.8degreesC that are higher than those of corresponding co-cyclics. Copyright (C) 2003 John Wiley Sons, Ltd.