@misc{kricheldorf_high_molar_2009, author={Kricheldorf, H.R.,Behnken, G.,Schwarz, G.,Simon, P.,Brinkmann, M.}, title={High Molar Mass Poly(trimethylene carbonate) by Ph2BiOEt and Ph2BiBr-Initiated Ring-Opening Polymerizations}, year={2009}, howpublished = {journal article}, doi = {https://doi.org/10.1080/10601320902724800}, abstract = {Trimethylene carbonate, (TMC), was polymerized in bulk with Ph2BiOEt or Ph2BiBr as initiators. The dependence of the molecular weight on the monomer-initiator ratio (M/I) and the MALDI-TOF (MT) mass spectra suggest that these polymerizations obey a coordination-insertion mechanism. Due to “back-biting” cyclic oligomers were also formed. With Ph2BiBr particularly high molecular weights were achieved (number averages, Mns, up to 340 times 103 Da), but the Mns were significantly higher than the M/Is. However, a satisfactory control of Mn was achieved by addition of tetraethylene glycol as coinitiator. In the case of Ph2BiOEt the Mns fell below the M/Is and only a crude control of the Mns was achieved. Both Bi-compounds were more reactive than Sn(II)2-ethylhexanoate (SnOct2) activated with ethanol. This difference was particularly conspicuous at temperatures below 100°C.}, note = {Online available at: \url{https://doi.org/10.1080/10601320902724800} (DOI). Kricheldorf, H.; Behnken, G.; Schwarz, G.; Simon, P.; Brinkmann, M.: High Molar Mass Poly(trimethylene carbonate) by Ph2BiOEt and Ph2BiBr-Initiated Ring-Opening Polymerizations. Journal of Macromolecular Science A. 2009. vol. 46, no. 4, 353-359. DOI: 10.1080/10601320902724800}}