The rapid increase in the use of plastics and the related sustainability issues, including the depletion of global petroleum reserves, have rightly sparked interest in the use of biobased polymer feedstocks. Thermosets cannot be remolded, processed, or recycled, and hence cannot be reused because of their permanent molecular architecture. Vitrimers have emerged as a novel polymer family capable of bridging the difference between thermoplastic and thermosets. Vitrimers enable unique recycling strategies, however, it is still important to understand where the raw material feedstocks originate from. Transesterification vitrimers derived from renewable resources are a massive opportunity, however, limited research has been conducted in this specific family of vitrimers. This review article provides a comprehensive overview of transesterification vitrimers produced from biobased monomers. The focus is on the biomass structural suitability with dynamic covalent chemistry, as well as the viability of the synthetic methods.

It is a great challenge to develop polymeric materials possessing multiple functionalities for their intrinsic properties. In our efforts to overcome this dilemma, we report a carbon nanotube (CNT)-doped polymer architecture design in this paper using a soft matrix synthesized from methacrylic acid and poly(ethylene glycol) methacrylate via reversible addition− fragmentation chain-transfer polymerization and further functionalized by 1-pyrenemethanol and doped with hard, stiff CNTs as fillers. The CNTs were dispersed evenly into the pyrenefunctionalized copolymers obtained via the solution blending method. Our approach is simple, low-energy-consuming, facile in operation, and highly efficient. The developed composites demonstrate high mechanical strength, self-healing ability, and high electrical conductivity. To further maximize the potential of our CNT-filled composites, we introduced a simple but effective means to align CNTs by directional stretching at elevated temperatures and so achieved significant mechanical and electrical reinforcement. The multifunctional composites produced in this paper have desirable properties for future applications such as conductive bioskins, healthcare monitoring sensors, and other functional conductive electronics.

Inspired by the chemical structure of chymotrypsin, we report an artificial catalytic triad with high catalytic efficiency for the transesterification reaction of vinyl trifluoroacetate and methanol. Rate accelerations of (kcat/kunc)...

Petroleum‐derived monomers are the most common building blocks for ester‐based thermosets. Bio‐derived thermoset elastomers are becoming viable alternatives to conventional thermosets. Herein, we developed a biobased vitrimer‐type thermoset elastomers using abundant and sustainable raspberry ketone as feedstock. We utilize raspberry ketone to create building blocks for dynamic oxime chemistry and crosslinked these through free radical polymerization with poly(ethylene glycol) methyl ether methacrylate as a comonomer. In contrast to other dynamic networks based on ester bonds, which need catalysts, this is undesirable since catalyst deactivation or leaching lowers its effect over time and may impair reuse. This network incorporates catalyst‐free bond exchange reactions in catalyst‐dependent polyester networks by substituting oxime‐esters for typical ester linkages. The elastomer exhibits stress relaxation, a low glass transition temperature (Tg) (−55 to −40.2°C) and tensile strength up to 5.2 ± 3.0 kPa. Furthermore, the dynamic oxime transesterification exchange mechanism allows elastomers to be reprocessed using a hot press at 160°C and 8 × 103 kPa pressure. After reprocessing, the tensile strength of elastomers can be recovered up to 78.1 ± 10.9%. This work integrates the principles of catalyst‐free dynamic exchange process and mechanical recycling coupled with biobased components to provide a rational solution towards conventional elastomers. In the future, these elastomers can be exploited for the development of hydrogels, recyclable elastomers, and commodity plastics.