NEW POLYMER SYNTHESES 106. POLYCARBONATES BY RING-OPENING POLYCONDENSATIONS OF TIN-CONTAINING MACROCYCLES WITH BISCHLOROFORMATES

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Abstract
2,2-Dibutyl-2-stanna-1,3-dioxepane (DSDOP) was polycon-densed with bisphenol-A bischloroformate (BABC) in bulk. Regardless of the reaction temperature and time only number average molecular weights (Mns) around 8,000–11,000 were obtained. 13C NMR spectra proved that the isolated copoly-carbonates possessed a random sequence. MALDI-TOF spectra of the crude and of the fractionated samples revealed that all samples contained macrocyclic polycarbonates. DSDOP was also used as initiator for the macrocyclic polymerization of-cap-rolactone. The resulting cyclic polylactones were then polycon-densed with BABC in situ. Mns in the range of 25,000–40,000 and Mws in the range of 40,000–65,000 were found based on polystyrene calibrated GPC measurements. Similar results were obtained when 1,6-hexanediol bischloroformate was used as electrophilic reaction partner in the polycondensation step.