Study of bulk chain coupling reactions. II. Reaction between bisoxazolones and amine-terminated polyether: Synthesis of polyether-block-polyamides

The bulk reactions between 2,2′-bis(4,4-dimethyl-5(4H)-oxazolone) ( B3 ) or 2,2′-(1,2-ethylene)-bis(4,4-dimethyl-5(4H)-oxazolone) ( B4 ) and amine-terminated polyether (Jeffamine ED-900) have been studied by SEC, and ¹H-and ¹³C-NMR and the resulting polymers were characterized by DSC and TGA. These chain coupling reactions have been applied to the synthesis of polyether-block-polyamides, starting from mixtures of amineterminated polyether and polyamide-12. High molar mass block copolymers were synthesized in the bulk within 1 h at 200°C and under atmospheric pressure, instead of several hours at 240°C under vacuum for the usual reaction between dicarboxy polyamides and dihydroxy polyethers. No other side reactions than the formation of a very small amount of 2-imidazolin-5-ones has been found. The DSC studies of block copolymers show the existence of a phase separation between the soft (polyether) and hard (polyamide) blocks. © 1993 John Wiley & Sons, Inc.