TY  - JOUR
A1  - Kricheldorf, Hans R.
A1  - Weidner, Steffen
A1  - Meyer, A.
T1  - About Polycondensation, Disproportionation, and Cyclization of Acetylated Poly(L-Lactide) Esters
JF  - Macromolecular Chemistry and Physics
N2  - 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.
KW  - MALDI-TOF MS
KW  - Polycondensation
KW  - Polylactides
KW  - Transesterifcation
PY  - 2024
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630349
DO  - https://doi.org/10.1002/macp.202400175
SN  - 1521-3935
VL  - 225
IS  - 19
PB  - Wiley VHC-Verlag
AN  - OPUS4-63034
LA  - eng
AD  - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER  -