Synthesis and ring opening polymerization of bicyclic lactones containing a tetrahydropyran ring. 2,5-Dioxabicyclo[2.2.2]octan-3-one

High-Tg PLA copolymers via base-catalyzed transesterification of PLA with 2,5,7-trioxabicyclo[2.2.2]octan-6-one

“…S5 †). This polymerization behavior of TOB is similar to the anionic ROP of 2,5-dioxabicyclo[2.2.2]octan-3-one reported by Hall et al 52 The powder XRD pattern of PTOB shows that it is a highly crystalline polymer (Fig. S6 †).…”

“…Hall and Okada systematically investigated the ROP of bicyclic lactones. [47][48][49][50][51][52][53][54][55] Recently, several other bicyclic lactones have also been synthesized and polymerized to generate high thermally stable polyesters with good mechanical properties and potential closed-loop recycling of monomers (Scheme 1). [55][56][57][58][59] The ROP of oxygen-containing bicyclic lactones (Scheme 1, VI-VIII) exhibits different polymerization behavior.…”

Ring-Opening Polymerization of a Bicyclic Lactone: Polyesters Derived from Norcamphor with Complete Chemical Recyclability

“…TGA revealed a T d,5% of 183 °C and a maximum rate decomposition temperature T d,max of 234 °C (Figure a). Comparing the decomposition temperature of PNCL to literature known polyesters bearing cyclic fragments in the backbone, its thermal stability is reduced. ,,,− , Decomposition temperatures of PNCL are similar to poly­(2-(2-hydroxyethoxy)­benzoate) (Scheme , Shaver 2016) . Subsequent work has shown that the thermal stability can be improved by O to S as well as alkyl substitution in the backbone. , Such strategies might also be promising for increasing the decomposition temperature of NCL -based polymers in the future.…”

“…The T g of PNCL ( T g = −9 °C) is increased more than 50 °C in relation to poly­( δ -valerolactone) . In comparison to polyesters bearing purely cyclopentyl or cyclohexyl backbones that often exhibit high T g or T m values, ,,, the CH 2 group in α -position to the carbonyl of PNCL presumably enables a higher chain flexibility. , …”

“…Inspired by the strategy of using ring-fused monomers for CRM and especially the hybridization approach of Chen et al, we were interested in whether this concept could be expanded to bicyclic lactones with a six-membered ring core structure and still yield chemically recyclable polyesters (Scheme ). ROP of six-membered bicyclic lactones is rarely reported in the literature, − and CRM has not yet been described. While δ -valerolactone has a relatively high ceiling temperature ( T c ), alkyl substitution strongly influences T c and monomer equilibrium concentration .…”