TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen A1 - Falkenhagen, Jana T1 - The role of transesterifications in reversible polycondensations and a reinvestigation of the Jacobson-Beckmann-Stockmayer experiments T2 - Polymer chemistry N2 - The polycondensations of adipic acid and 1,10-decanediol catalyzed by toluene sulfonic acid (TSA) were reinvestigated using MALDI TOF mass spectrometry and NMR spectroscopy. Unexpected reactions of TSA were detected along with incomplete conversion of the monomers. Furthermore, transesterification reactions of end-capped poly(1,10-decanediol adipate) and end-capped poly(ε-caprolactone) catalyzed by TSA were studied. Despite the quite different (ionic) reaction mechanisms, it was found that for polycondensations performed in bulk intermolecular transesterification is more efficient than the intramolecular “back-biting”; this scenario was not considered in the Jacobson–Stockmayer theory of reversible polycondensations. These results also confirm that the Jacobson–Stockmayer explanation of reversible polycondensations solely on the basis of ring chain equilibration is not only devoid of any experimental evidence, but also in contradiction to the results elaborated in this work. PB - RSC Publ. CY - Cambridge KW - Polylactide KW - MALDI-TOF MS KW - Polycondensation PY - 2022 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/54340 AN - OPUS4-54340 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543402 SN - 1759-9962 SP - 1 EP - 9 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany