END-GROUP ANALYSIS OF POLY(PHENYL GLYCIDYL ETHER) .2. HYDROXYLIC GROUPS USING F-19 NUCLEAR-MAGNETIC-RESONANCE

The hydroxylic end-groups in the soluble fraction of poly(phenyl glyci dyl ether) (PPGE) obtained with the aluminium isopropoxide (AIP)/ZnCl2 initiator system are studied using F-19 NMR spectroscopy. Derivatizat ion as trifluoroacetate esters affords poor structural information and handle difficulties. Hexafluoroacetone (HFA) hemiketalic adducts are much more easily prepared and offer more information, allowing not onl y to distinguish between primary and secondary alcohols but showing a clear sensitivity to the tacticity. This method is successful to calcu late the percentage of hydroxylic end-group in the polymer chain. In t he case of an irregular PPGE sample, obtained with AIP alone as initia tor, it is possible to identify three different hydroxylic end-groups.