TY - GEN A1 - Weidner, Steffen T1 - Cyclic polylactides via ring-expansion polymerization N2 - We will report on a new kind of ring-expansion polymerization (REP) of cyclic esters based of three classes of catalysts. In contrast to REP described previously these new polymerizations are characterized by a self-extrusion of the catalysts resulting in cyclic homopolyesters as the only reaction product. These REP of L-lactide were performed in bulk at temperatures between 100 and 180°C without racemization. A simplified scheme of a REP catalyzed by BuCa or SnBi is presented below. With meso-lactide temperatures down to 60°C were realized. Depending on catalyst, time and temperature with equal quantities of even and odd-numbered cycles a strong predominance of either even or odd-numbered cycles was found. T2 - 255th ACS National Meeting CY - New Orleans, LA, USA DA - 18.03.2018 KW - MALDI-TOF MS KW - Poly(lactide) KW - Polymerisation KW - Catalysts PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/44833 AN - OPUS4-44833 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany