TY  - JOUR
A1  - Kricheldorf, Hans R.
A1  - Weidner, Steffen
T1  - H2O-Initiated Polymerization of L-Lactide
JF  - Journal of Polymers and the Environment
N2  - Water-initiated ring-opening polymerizations (ROPs) of L-lactide (LA) were performed in bulk at 140 °C, whereupon 11 different salts or complexes of low-toxic metal ions such as tin (II), Zn(II), Zr(IV), and Bi(III) were used as catalysts. Only four catalysts gave satisfactory results despite a long reaction time (24 h). The influence of the temperature was studied with tin (II) 2-ethylhexanoate (SnOct2), dibutyltin oxide (Bu2SnO), and zinc bis-acetylacetonate (Zn(acac)2) and zirconium acetylacetonate (Zr(acac)4). With SnOct2, Bu2SnO and Zr(acac)4 the time was varied at 140 °C to compare their reactivity. Furthermore, two series of ROPs were carried out with variation of the LA/H2O ratio to verify the control of the molecular weight by the monomer-initiator ratio. Bi- or tri-modal molecular weight distributions (MWD) were found for most of the ROPs and bimodal melting endotherms in the differential scanning calorimetry (DSC) heating traces. The thickness and dependence of the 3D packing of the crystallites were monitored by small-angle X-ray scattering (SAXS) measurements.
KW  - MALDI-TOF MS
KW  - Polylactide
KW  - Ring-opening polymerization
KW  - Crystallization
PY  - 2025
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628761
DO  - https://doi.org/10.1007/s10924-025-03565-w
SN  - 1572-8919
VL  - 33
IS  - 6
SP  - 2843
EP  - 2857
PB  - Springer Science and Business Media LLC
CY  - New York, NY
AN  - OPUS4-62876
LA  - eng
AD  - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER  -