Towards high-performance sustainable polymers via isomerization-driven irreversible ring-opening polymerization of five-membered thionolactones

Chemically recyclable polymer materials: polymerization and depolymerization cycles

“…[131][132][133][134] Very recently, Hong reported an unusual irreversible ring-opening polymerization (IROP) of biomassderived five-membered thionolactones (TnBL) via a S/O isomerization process promoted by t BuP 4 (Scheme 13). 135 The obtained poly(thiolactone) showed comparable thermal and mechanical properties to commercial petroleum-based lowdensity polyethylene. Besides, the authors also studied the degradability of the produced polymer.…”

Thiocarbonyl chemistry in polymer science

“…A recent contribution demonstrated that even 5-membered thionolactones (19) can undergo ring-opening polymerization, using a basic phosphorous catalyst (such as BEMP) and ambient conditions. 105 Here, the thioester product is the only polymer produced, utilising the S-O isomerisation as the main driving force and overcoming the lack of ring-strain. [112][113][114] However, two competing side reactions occur.…”

“…Similar polymerization of ethylene carbonate leads to ether linkages due to loss of carbon dioxide 103 Organocatalytic Retention of thiocarbonyl 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD, organocatalyst) and 4-methyl benzyl alcohol (initiator) 104 Proceeds via retention of the thiocarbonyl bond, without an S-O isomerism, different to 17, reportedly due to the use of an organocatalyst; 18a was shown to polymerize the fastest due the additional ring strain of the trans configuration of the xanthate ring; 18b was thought to be faster than 18c due to C-S bonds being weaker and easier to break than C-O bonds Organocatalytic S-O isomerism BEMP, r.t 105. Produces only the thioester polymer, through an irreversible mechanism; similar to the DBU ringopening of ε-thionocaprolactone 16, however no trace of the thionoester is found Organocatalytic Retention of thiocarbonyl DMAP, DBU, thiourea106 …”

Efficient and Selective Chemical Recycling of CO2‐Based Alicyclic Polycarbonates via Catalytic Pyrolysis

“…Many of them that we frequently use have extremely short lifetimes, but the corresponding plastics wastes can persist for many years in the environment due to chemically inert nature of their compositions, such as polyethylene and poly(ethylene terephthalate) [3–5] . Therefore, chemical recycling to monomers represents an attractive strategy for circular polymer economy, since the recovered monomers can be reused to produce polymers with a virgin quality [6–12] . Recently, the chemical recycling of various new polyethers, [13, 14] polyesters, [6–8, 15–19] polycarbonates [9, 20–25] and sulfur containing polymers [12, 26–29] to respective monomers has been demonstrated, and the development of completely recyclable polymers has become an emerging frontier in polymer chemistry.…”