CHROMATOGRAPHIC INVESTIGATIONS OF POLYACETALS IN THE CRITICAL RANGE OF LIQUID-CHROMATOGRAPHY .2. DETERMINATION OF FUNCTIONALITY AND MOLECULAR-WEIGHT DISTRIBUTIONS IN -BIS(9-ANTHRYLMETHYLPOLY(1,3,6-TRIOXACYCLOOCTANE)S OBTAINED BY ACTIVE CHAIN-END MECHANISM

The fractions obtained by cationic active chain-end polymerization of 1,3,6-trioxacy looctane initiated with (CF3SO2)(2)O (I), CF3SO3-+OCC6H 4CO+-O3SCF3 (II) and (C6H5)(3)C+PF6- (III) were investigated using hig h-performance liquid chromatography (HPLC) at the ''critical point'' o f adsorption. The propagating species were converted into 9-anthrylmet hyl groups by suitable reactions of termination or transformation. The ir incorporation made the chain ends detectable in the ultraviolet spe ctrum. The samples were separated at conditions specified for poly(1,3 ,6-trioxacyclooctane)s (polyTOCs) obtained with (CF3SO2)(2)O as initia tor. The functionality and molecular weight distribution of polyTOCs o btained with mono- and bifunctional initiators and with different coun terions were compared and discussed. In the reaction mixtures oligomer s of undesired functionality were detected irrespective of the usage o f mono- or even bifunctional initiators. A correct method was used to determine the completeness of the separation and to calculate the perc entages of the individual fractions. The order of initiators depending on the amount of the undesired end-functionality fractions in the pro ducts obtained has been established. Attempts were made to elucidate t he reactions complicating the cationic chain-end polymerization of cyc lic acetals and leading to a mixture of cyclic, dead, monofunctional a nd bifunctional oligomers and polymers. The results were summarized an d compared with functionality and molecular weight distributions of ol igo(1,3,6-trioxacyclooctane)s obtained by ''activated monomer mechanis m'' which have been discussed in the first paper of this series.