NEW RESULTS OF THE FREE-RADICAL RING-OPENING POLYMERIZATION

The reaction of 5-ring ketene-O,N-acetals with peroxides was investiga ted. It was shown that benzoyl peroxide adds to monomers 5a and 5b by ring opening, giving the corresponding linear diester amides 6a and 6b , respectively. The ketene-O,N-acetal 5c adds benzoyl peroxide, withou t ring opening, by addition to the exomethylene group, giving the cycl ic-O,N-acetal diester 6c. With phthaloyl peroxide cyclic esteramides 7 and oligomeric products are formed. The chemical structures of the ad dition products were confirmed by NMR spectra and elemental analysis. (C) 1994 John Wiley and Sons, Inc.