Ring polymers are synthesized using a cyclic bifunctional thioester as initiator for REP of thiiranes. PMT yields satisfactory results, whereas polymerization with MT appears to develop dead polymeric material as by‐product and TBMT gives only negligible conversion rates. The process produces high yields and high conversion rates. The corresponding molecular weight distributions show increasing broadening and multimodal character with increasing reaction time due to thermodynamically controlled ring‐merging reactions between macrocycles. The polymerization rate of PMT obeys a pseudo first‐order kinetics with an activation energy of 38.8 kJ mol−1. 1H NMR, ESI‐MS, and glass transition temperatures independent of the molecular weight demonstrate the presence of cyclic polymer. magnified image

The behavior of the ring-expansion homopolymerization of 2 (phenoxymethyl)thiirane (PMT) and propylene sulfi de (PS), respectively, with thiazolidine-2,4-dione (TZD) as a cyclic initiator is investigated. The polymerizations show steadily growing molar masses with increasing monomer conversions. In addition, reversible merging reactions between rings are observed, with up to six merged macrocycles formed. The degree of merging is strongly dependent on the initial monomer concentration, whereas temperature has only a small impact. Under optimized conditions, ringpoly(PMT) polymer with values of M n up to 50 250 g mol − 1 and dispersities down to 1.11 can be synthesized. DSC and ESI-MS measurements of the novel ring -poly(PS) prove the formation of ring polymer having topological purity above 95%.

Polycyclic polymers made from cyclic (ABC)n-multiblock-copolymers that may undergo self-complementary hydrogen bonds within the individual rings show extraordinary material properties.

Correction for ‘Titin-mimicking polycyclic polymers with shape regeneration and healing properties’ by Jan-Hendrik Schuetz et al., Polym. Chem., 2015, DOI: 10.1039/c4py01458h.