TY - JOUR A1 - Kricheldorf, H. A1 - Weidner, Steffen A1 - Meyer, A. T1 - Syntheses of Polyglycolide via Polycondensation: A Reinvestigation T2 - Macromolecular Chemistry and Physics N2 - The Na salt of chloroacetic acid is condensed in suspension. Furthermore,glycolic acid is condensed in bulk or in concentrated solution by means of SnCl2 or 4-toluene sulfonic acid (TSA) as catalysts. The temperatures are varied from 160 to 200°C and the time from 1 to 5 days. Low molar mass cyclic poly(glycolic acid) (PGA) is detected by means of matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry in most PGAs. A predominance of certain cycles having an even number of repeat units is observed suggesting a thermodynamically favored formation of extended-ring crystals. Extremely high melting temperatures (up to 237.5°C)and high melting enthalpies are found for polycondensations with TSA in 1,2-dichlorobenzene. PB - Wiley VHC-Verlag KW - MALDI TOF MS KW - Polycondensation KW - Polyglycolide KW - Cyclization PY - 2024 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/59685 AN - OPUS4-59685 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596856 IS - 2300397 SP - 1 EP - 7 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany