NEW POLYMER SYNTHESES - 100 - MULTIBLOCK COPOLYESTERS BY COMBINED MACROCYCLIC POLYMERIZATION AND SILICON-MEDIATED POLYCONDENSATION

Using 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP) as cyclic initiator t he macrocyclic polymerizations of epsilon-caprolactone were conducted in bulk at 80 degrees C at monomer/initiator ratios of 20/1. The resul ting tin-containing supermacrocycles were reacted in situ with an exce ss of isophthaloyl chloride, and this reaction mixture was polycondens ed with silylated Bisphenol A at temperatures between 150 and 300 degr ees C. The characterization of the isolated copolyesters by DSC measur ements and H-1 NMR and C-13 NMR spectroscopy proved that they possess a perfect multiblock structure up to a reaction temperature of 240 deg rees C. At higher temperatures transesterification causes a more or le ss perfect randomization of the sequence. In a second series of combin ed ring-opening polymerizations and ring-opening polycondensations (RO PPOC) silylated methylhydroquinone and 1,10-bis(4-chlorophenoxy)decane were used as comonomers of the macrocyclic poly(epsilon-caprolactone) . The isolated multiblock copolyesters showed a two phasic melt with a n isotropic phase containing the polylactone blocks and a nematic phas e consisting of the aromatic blocks. The relationship between block le ngths and phase separation is discussed.