The preparation of multifunctional polymer materials from natural renewable resources via a simple method meets ever-expanding practical applications and matches sustainable development strategies. We synthesized a multifunctional polymer with a dual-dynamic three-dimensional (3D) crosslinked network of hydrogen bonds and dynamic imine bonds from epoxy soybean oil and vanillin via a simple preparation process. The as-prepared polymers have controllable mechanical strength between ultrahigh stretchability (strain at break: over 2800%) and rigidity (bending strength: 25.51 ± 0.27 MPa with a strain at break of approximately 2%) via varying imine bonds to readily tailored. They can be used as reusable adhesive. The highly dynamic nature of the hydrogen and imine bonds allows the damaged polymer to self-heal, and it can be re-recycled multiple times. The healed and recycled polymer regains most of its mechanical strength. The polymer exhibits both permanent and temporary shape memory at the same temperature via solid state plasticity, i.e., topological polymer network rearrangement resulting from dynamic bond exchange. Furthermore, our polymers can be used to prepare conductive adhesives/composites that are self-healing, recyclable, and re-shapable.

With rising environmental concerns and depletion of petrochemical resources, biomass-based chemicals have been paid more attention. Polyvinyl chloride (PVC) plasticizers derived from biomass resources (vegetable oil, cardanol, vegetable fatty acid, glycerol and citric acid) have been widely studied to replace petroleum-based o-phthalate plasticizers. These bio-based plasticizers mainly include epoxidized plasticizer, polyester plasticizer, macromolecular plasticizer, flame retardant plasticizer, citric acid ester plasticizer, glyceryl ester plasticizer and internal plasticizer. Bio-based plasticizers with the advantages of renewability, degradability, hypotoxicity, excellent solvent resistant extraction and plasticizing performances make them potential to replace o-phthalate plasticizers partially or totally. In this review, we classify different types of bio-based plasticizers according to their chemical structure and function, and highlight recent advances in multifunctional applications of bio-based plasticizers in PVC products. This study will increase the interest of researchers in bio-based plasticizers and the development of new ideas in this field.

Lignin is readily available as a by-product from the pulp and paper industry. It is considered to be a promising substitute for phenol in phenol-formaldehyde (PF) resin synthesis, given the increasing concerns of the shortage of fossil resources and the environmental impact from petroleum-based products. One hurdle that prevents the commercial utilization of lignin is its low reactivity due to its chemical structure. Many efforts have been made to improve its reactivity by modification and/or depolymerization of lignin molecules. Methylolation and phenolation are the two most studied modification approaches aimed at introducing reactive functional groups to lignin molecules. Modified lignin from these two methods could partially replace phenol in PF resin synthesis. Demethylation of lignin could effectively increase the reactivity of lignin by forming catechol moieties in the lignin macromolecule. Other methods, including reduction, oxidation, and hydrolysis, have also been studied to improve the reactivity of lignin as well as to produce phenolic compounds from lignin. Most current methods of lignin modification are not economically attractive. One can expect that efforts will be continued, aimed at improving the utilization of lignin for value-added products.