COPOLYESTERAMIDES .8. A COMPARISON OF SUBSTANTIALLY ALTERNATING 12-OXYDODECANOYL OMEGA-IMINOALKANOYL POLYESTERAMIDES WITH EQUIVALENT RANDOMCOPOLYMERS/

The polycondensation of methyl N-(12-hydroxydodecanoyl)-omega-aminoalk anoates (HO(CH2)11CONH(CH2)xCOOCH3) has been studied as a source of th e alternating polyesteramides [O(CH2)11CONH(CH2)xCO]n, and the propert ies of the products compared with those of equivalent random copolymer s of similar co-unit ratio. Polymerization of the esters with x = 10 a nd 11 occurred straight-forwardly, giving crystalline products which w ere distinguishable from the random counterparts by DSC but not by 67 MHz C-13 NMR. For x = 5 the reaction was complicated by progressive pa rtial elimination of the amide moiety as 6-hexanolactam and by transam idation leading, for the polymer of highest amide content obtained, to an imperfect structure with ca. 76% of the sub-units in alternating a rrangement, the remainder being composed of oligoester and diamide uni ts. This deviation from ideality has been elucidated by a study of the C-13 NMR spectra of a wide range of model compounds which has yielded criteria for the recognition of oligomeric iminohexanoyl units, and b y the NMR and MS examination of the products of aminolytic degradation . The results explain the multiple signals found in the C-13 NMR spect ra of the imperfectly alternating polymer (x = 5) and of its random an alogues.