63034 2024 eng 19 225 article Wiley VHC-Verlag 1 -- -- -- L-lactide (LA) is polymerized with ethyl L-lactate or trifluoroethanol as initiators (LA/In = 30/1), and the resulting poly(L-lactide) esters are acetylated with acetic anhydride. The acetylated PLA esters are mixed with SnOct2, dibutyltin bis(4-chlorophenoxide), or dibutyltin bis(pentafluorophenoxide) in solution and crystallized at 120 °C. The doped crystals are annealed at 140 °C or at 160 °C for 7, 14, and 28 days, and the chemical modifications that occurred in the solid state are monitored by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) measurements. All catalysts promoted polycondensation, while no significant formation of cycles is observed. However, in the presence of SnOct2, disproportionation of chains occurred upon annealing at 120 or 140 °C, and crystallites consisting of extended chains with Mn values ≈3500 – 3600 and low dispersities (Ð < 1.5) are formed. Macromolecular Chemistry and Physics 10.1002/macp.202400175 1521-3935 urn:nbn:de:kobv:b43-630349 publish 05.05.2025 false true Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International Hans R. Kricheldorf Steffen Weidner A. Meyer eng uncontrolled MALDI-TOF MS eng uncontrolled Polycondensation eng uncontrolled Polylactides eng uncontrolled Transesterifcation Analytische Chemie Ingenieurwissenschaften und zugeordnete Tätigkeiten 6 Materialchemie 6.3 Strukturanalytik Material Degradationsmechanismen Chemie und Prozesstechnik Chemische Charakterisierung und Spurenanalytik Verlagsliteratur Datei für die Öffentlichkeit verfügbar ("Open Access") Wissenschaftliche Artikel der BAM Bundesanstalt für Materialforschung und -prüfung (BAM) https://opus4.kobv.de/opus4-bam/files/63034/MCP 2024 About Polycondensation Disproportionation and Cyclization of Acetylated.pdf