1:3 ABAA sequence-regulated substituted polymethylenes via alternating radical copolymerization of methyl cinnamate and maleic anhydride followed by post-polymerization reactions

Degradable Alternating Copolymers from Living Radical Copolymerization of Natural Levoglucosenone and Dienes

Here, we present an efficient synthetic route to biobased alternating copolymers via the living radical copolymerization of naturally occurring levoglucosenone (LGO) and dienes. By employing reversible addition-fragmentation chain transfer (RAFT) polymerization, well-defined LGO-derived copolymers were readily synthesized featuring high degrees of alternation, well-controlled molecular weights, and excellent end-group fidelity. Additionally, the alternating copolymers exhibited thermal and mechanical properties comparable to those of the commodity polystyrene. Furthermore, an on-demand metathesis degradation was identified, highlighting their potential as degradable materials.

Recent developments towards performance-enhancing lignin-based polymers

This review examines recent strategies, challenges, and future opportunities in preparing high-performance polymeric materials from lignin and its derivable compounds.

Biobased Polymers via Radical Homopolymerization and Copolymerization of a Series of Terpenoid-Derived Conjugated Dienes with exo-Methylene and 6-Membered Ring

A series of exo-methylene 6-membered ring conjugated dienes, which are directly or indirectly obtained from terpenoids, such as β-phellandrene, carvone, piperitone, and verbenone, were radically polymerized. Although their radical homopolymerizations were very slow, radical copolymerizations proceeded well with various common vinyl monomers, such as methyl acrylate (MA), acrylonitrile (AN), methyl methacrylate (MMA), and styrene (St), resulting in copolymers with comparable incorporation ratios of bio-based cyclic conjugated monomer units ranging from 40 to 60 mol% at a 1:1 feed ratio. The monomer reactivity ratios when using AN as a comonomer were close to 0, whereas those with St were approximately 0.5 to 1, indicating that these diene monomers can be considered electron-rich monomers. Reversible addition fragmentation chain-transfer (RAFT) copolymerizations with MA, AN, MMA, and St were all successful when using S-cumyl-S'-butyl trithiocarbonate (CBTC) as the RAFT agent resulting in copolymers with controlled molecular weights. The copolymers obtained with AN, MMA, or St showed glass transition temperatures (Tg) similar to those of common vinyl polymers (Tg ~ 100 °C), indicating that biobased cyclic structures were successfully incorporated into commodity polymers without losing good thermal properties.