Synthesis and MALDI-TOF MS Characterization of High Molecular Weight Poly(1,2-dihydroxybenzene phthalates) Obtained by Uncatalyzed Bulk Polymerization of O , O ‘-Phthalid-3-ylidenecatechol or 4-Methyl- O , O ‘-phthalid-3-ylidenecatechol

A new procedure to obtain high molecular weight poly(1,2-dihydroxybenzene phthalates) by bulk polymerization of some spiro-compounds is described. O, O ‘-Phthalid-3-ylidenecatechol ( I ) and 4-methyl- O, O ‘-phthalid-3-ylidenecatechol ( II ) spiro-compounds have been synthesized and used as monomers. Poly(1,2-dihydroxybenzene phthalate) ( III ) and poly(1,2-dihydroxy-4-methylbenzene phthalate) ( IV ) have been prepared by heating at 200 °C of spiro-compounds I and II, respectively, without addition of catalyst. The resulting polyesters III and IV have been characterized by GPC, TG, DSC, NMR, FAB-MS, and MALDI-TOF MS analyses. The GPC curves of the obtained materials showed that high molecular weight polyesters, containing only a very little amount of low molecular weight oligomers, have been formed. The structural characterization of these polyesters by FAB and MALDI-TOF mass spectrometric analyses showed that they are constituted exclusively of open-chain macromolecules having both hydroxy end-groups. Data collected suggest that in the bulk polymerization of spiro-compounds I and II a possible chain growth mechanism of polymerization is active, which is strongly inhibited by acid species.