Sustainable elastomers have undergone explosive growth in recent years, partly due to the resurgence of biobased materials prepared from renewable natural resources. However, mounting challenges still prevail: How can the chemical compositions and macromolecular architectures of sustainable polymers be controlled and broadened? How can their processability and recyclability be enabled? How can they compete with petroleum-based counterparts in both cost and performance? Molecular-biomass-derived polymers, such as polymyrcene, polymenthide, and poly(ε-decalactone), have been employed for constructing thermoplastic elastomers (TPEs). Plant oils are widely used for fabricating thermoset elastomers. We use abundant biomass, such as plant oils, cellulose, rosin acids, and lignin, to develop elastomers covering a wide range of structure-property relationships in the hope of delivering better performance. In this Account, recent progress in preparing monomers and TPEs from biomass is first reviewed. ABA triblock copolymer TPEs were obtained with a soft middle block containing a soybean-oil-based monomer and hard outer blocks containing styrene. In addition, a combination of biobased monomers from rosin acids and soybean oil was formulated to prepare triblock copolymer TPEs. Together with the above-mentioned approaches based on block copolymers, multigraft copolymers with a soft backbone and rigid side chains are recognized as the first-generation and second-generation TPEs, respectively. It has been recently demonstrated that multigraft copolymers with a rigid backbone and elastic side chains can also be used as a novel architecture of TPEs. Natural polymers, such as cellulose and lignin, are utilized as a stiff, macromolecular backbone. Cellulose/lignin graft copolymers with side chains containing a copolymer of methyl methacrylate and butyl acrylate exhibited excellent elastic properties. Cellulose graft copolymers with biomass-derived polymers as side chains were further explored to enhance the overall sustainability. Isoprene polymers were grafted from a cellulosic backbone to afford Cell-g-polyisoprene copolymers. Via cross-linking of these graft copolymers, human-skin-mimic elastomers and high resilient elastomers with a well-defined network structure were achieved. The mechanical properties of these resilient elastomers could be finely controlled by tuning the cellulose content. As isoprene can be produced by engineering of microorganisms, these elastomers could be a renewable alternative to petroleum products. In summary, triblock copolymer and graft copolymer TPEs with biomass components, skin-mimic elastomers, high resilient biobased elastomers, and engineering of macromolecular architectures for elastomers are discussed. These approaches and design provide us knowledge on the potential to make sustainable elastomers for various applications to compete with petroleum-based counterparts.

Amidation of plant oils with amino alcohols was methodologically examined.

Instant strong and responsive underwater adhesion is significant for many biomedical, industrial, and household applications. However, underwater adhesives simultaneously possessing these advantages are challenging to fabricate because strong and responsive adhesions are usually opposing properties. Herein, we have prepared bioinspired supramolecular polymeric adhesives containing complementary nucleobase moieties in nucleic acids and have demonstrated instantaneous underwater adhesion with an adhesion strength reaching as high as 1.5 MPa. Strong underwater adhesion is attributed to the high capability of the adhesives to substantially remove the interfacial water, which can be further modulated by temperature, light, and pH. Excellent underwater adhesion performances have been achieved on various substrates and under distinct aqueous conditions, showcasing the wide applications of the bioinspired nucleobase-containing adhesives developed here. This work opens up a new opportunity for fabricating underwater adhesives for diverse applications with the combined advantages of instant strong and responsive adhesion.

Biomass-derived protein adhesives have gained considerable attention as a replacement for formaldehyde-based resins in industry. However, for biobased structural adhesives, water-tolerance polymeric structures were highly necessary to realize adhesion and cohesion behaviors. In this work, a new dual-network soy-based adhesive consisting of nanocross-linkers (aldehyde- and dopamine-bearing, cellulose nanofibers, OCNF-CA) was successfully designed and prepared, and the cross-linking structure–property relationship of the adhesive was systematically studied. The double cross-linked structure considerably facilitated the preferential detachment/rupture of the rigid protein chain network, therefore significantly improving the filler dispersion and energy dissipation efficiency. Strong and tough mechanical performance was achieved, with a maximum tensile strength of 8.42 MPa and a toughness of 6.06 MJ/m3. Thanks to the tailored moisture-insensitive adhesion interface resulting from the sufficient free-catechol groups on the optimal network, this dual-network adhesive exhibited high and stable adhesion properties as determined by the ultimate shear stress for glued plywood. This work provides a novel strategy to design a hybrid cross-linking network for preparing high-performance environmentally friendly adhesives in wood-based panel industries.