TY - JOUR A1 - Weidner, Steffen A1 - Scheliga, F. A1 - Kricheldorf, H.R. T1 - Low-temperature polymerization of epsilon-caprolactone catalyzed by cerium triflates N2 - Using 22 metal triflates as catalysts, ε-caprolactone is polymerized at 22 °C in bulk. Only five relatively acidic triflates prove active. Three triflates, including the neutral Sm3+, are active using water as initiator. A very low content of cyclics is found in all the experiments. With Ce3+ and Ce4+, polymerizations are performed in CH2Cl2 and in bulk at 2 °C and 22 °C. Low dispersities (down to 1.1) are obtained. At 22 °C, Ce4+ and, even better, Ce3+ also catalyze syntheses of CO2H- and CH2OH-terminated polycaprolactones, whereby higher dispersities and larger fractions of cyclics are obtained. Further polymerizations and polycondensations are catalyzed with protic acids. The results can be explained by a proton-catalyzed activated monomer mechanism. KW - Epsilon-caprolactone KW - Cyclization KW - Metal triflates KW - Polycondensation KW - Ring-opening polymerization PY - 2013 U6 - https://doi.org/10.1002/macp.201300279 SN - 1022-1352 SN - 1521-3935 VL - 214 IS - 18 SP - 2043 EP - 2053 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -