TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - Ring-expansion polymerization of meso-lactide catalyzed by dibutyltin derivatives T2 - Journal of Polymer Science: Polymer Chemistry N2 - Meso-Lactide was polymerized in bulk at 60, 80, and 100 °C by means of three different types of catalysts: dibutyltinsulfides (2,2-dibutyl-2-stanna-1,3-dithiolane and 2,20-dibutyl-2-stanna-1,3-dithiane), dibutyltin derivatives of substituted cate-chols (BuCa, CyCa, and BzCa), and dibutyltin derivatives of2,2 dihydroxybiphenyl (SnBi) and 2,2-dihydroxy-1,10-binaphthyl(SnNa. Only the latter two catalysts were active at 60 °C. The architecture of the resulting polylactides depends very much on the structure of the catalyst and on the temperature. At the lowest temperature (60 °C), SnBi and SnNa mainly yielded even-numbered linear chains, but SnNa also yielded even-numbered cycles at 100 °C and short reaction times. In contrast,BuCa, CyCa, and BzCa mainly yielded odd-numbered cycles, although the same catalysts yielded even-numbered linear chains when benzylalcohol was added. PB - Wiley Periodicals Inc. KW - MALDI-TOF MS KW - Cyclisation KW - Catalysts KW - Polyester KW - Polymerization PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/44278 AN - OPUS4-44278 SN - 1099-0518 SN - 0022-3832 VL - 56 IS - 7 SP - 749 EP - 759 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany