THERMAL POLYMERIZATION OF 4-METHOXY-PHENY L-ETHYNYL-KETONE, A MODEL OF PRECURSORS OF THERMOSTABLE POLYMERS

Size exclusion chromatography (SEC) and spectroscopic analyses (i.r. H -1 and C-13 NMR) are used to study the thermal bulk polymerization of 4-methoxy-phenyl ethynyl ketone. Liquid-solid chromatography is the te chnique employed to isolate oligomeric fractions; among these, 1,3,5-c yclotrimer is isolated and characterized. On the other hand, the study of the polymeric main fraction leads to the conclusion that placement s are mainly tail to tail ones; the conventional head to tail placemen ts are in a lesser proportion and they account for the formation of th e cyclotrimer. A comprehensive reaction mechanism is proposed.