One‐pot orthogonal thiol‐ene click polymerization and ring‐opening grafting reaction of CO 2 ‐based disubstituted δ‐valerolactone

Polyester Platform with High Refractive Indices and Closed-Loop Recyclability from CO2, 1,3-Butadiene, and Thiols

α-Ethylidene-δ-vinyl-δ-valerolactone (EVL) is the only intermediate to synthesize copolymers of CO2 with 1,3-butadiene whose ring-opening polymerization (ROP), however, is obstructed by the tiglate group. In the contribution, EVL derivatives are synthesized through a Michael addition reaction to saturate the conjugated double bond as well as introduce various groups to synthesize polyesters with designable molecular weights (Mn = 6.9-12.8 kg·mol-1), narrow dispersities (Đ = 1.08-1.19), tunable glass-transition temperatures (Tg = -45-3 °C), and excellent refractive indices (nd = 1.64-1.79) via living and controlled ROP. The obtained polyesters are able to be recycled to the corresponding monomers, which can prepare comparable polymers with identical side groups, realizing the homorecycling. In addition, the retro-Michael addition reaction is established and employed, realizing heterorecycling, which can alter properties during recycling. We propose a strategy for EVL derivatives and establish the corresponding polyester platform with not only high refractive indices and tunable Tgs, but also the ability to tailor properties during recycling.

Sustainable Copolymer Synthesis from Carbon Dioxide and Butadiene

Carbon dioxide (CO2) has long been recognized as an ideal C1 feedstock comonomer for producing sustainable materials because it is renewable, abundant, and cost-effective. However, activating CO2 presents a significant challenge because it is highly oxidized and stable. A CO2/butadiene-derived δ-valerolactone (EVP), generated via palladium-catalyzed telomerization between CO2 and butadiene, has emerged as an attractive intermediate for producing sustainable copolymers from CO2 and butadiene. Owing to the presence of two active carbon-carbon double bonds and a lactone unit, EVP serves as a versatile intermediate for creating sustainable copolymers with a CO2 content of up to 29 wt % (33 mol %). In this Review, advances in the synthesis of copolymers from CO2 and butadiene with divergent structures through various polymerization protocols have been summarized. Achievements made in homo- and copolymerization of EVP or its derivatives are comprehensively reviewed, while the postmodification of the obtained copolymers to access new polymers are also discussed. Meanwhile, potential applications of the obtained copolymers are also discussed. The literature references were sorted into sections based on polymerization strategies and mechanisms, facilitating readers in gaining a comprehensive view of the present chemistry landscape and inspiring innovative approaches to synthesizing novel CO2-derived copolymers.

The Divergent Reactivity of Lactones Derived from Butadiene and Carbon Dioxide in Macromolecular Synthesis

The catalytic conversion of carbon dioxide and 1,3-butadiene into unsaturated lactone monomers provides an efficient route for converting sustainable carbon feedstocks into novel macromolecules. The chemical reactivity of this monomer is reviewed in order to highlight the many viable mechanistic pathways. Polymerization strategies, monomer alterations, and post-polymerization modifications are covered. The polymerization methods include radical, coordination, conjugate addition, ring-opening, olefin metathesis, and thiol-ene chemistries. Materials derived from these processes possess a wide range of function including responsiveness, degradability, adhesion, recyclability, and self-assembly. These aspects along with the advances in polymer chemistry that make them possible are discussed, along with a perspective on the future directions of the field.