Renewable polymers with excellent stretchability and self-healing ability are interesting for a wide range of applications. A novel type of wholly biobased, self-healing, polyamide-based thermoplastic elastomer was synthesized using a fatty dimer acid and a fatty dimer amine, both containing multiple alkyl chains, through facile one-pot condensation polymerization under different polymerization times. The resulting elastomer shows superior stretchabiblity (up to 2286%), high toughness, and excellent shape recovery after being stretched to different strains. This elastomer also displays high room temperature autonomous self-healing efficiency after fracture and zero water uptake during water immersion. The highly entangled main chain, the multiple dangling chains, the abundant reversible physical bonds, the inter-molecular diffusion and the low ratio of amide to methylene 2 group within the elastomer are responsible for these extraordinary properties. The polymerization time influences the properties of the elastomer. The use of the optimal self-healing thermoplastic elastomer in anti-corrosion coating, piezoresistive sensing and highly stretchable fibres is also demonstrated. The elastomer coating prevents stainless-steel products from corrosion in a salty environment due to its superhydrophobicity. The elastomer serves as a robust flexible substrate for creating self-healing piezoresistive sensors with excellent repeatability and self-healing efficiency.The elastomer fibre yarn can be stretched to 950% of its original length confirming its outstanding stretchability.

Thermoplastic elastomers (TPEs) are useful in various engineering and healthcare applications. A new fully biobased polyamide TPE (PA36,9) with medium hardness is reported. The elastomer is synthesized using a fatty dimer amine and azelaic acid, via one-pot melt condensation polymerization. The resulting elastomer shows a melting temperature of 83.6 °C, a medium hardness (Shore A/Shore D = 90/35), a large elongation at break (1220%), good resilience, and impact resistance, while maintaining high tensile strength (31.8 MPa), low density (0.93 g cm −3 ), and hydrophobicity. The chemical structure of the repeating unit, together with the molecular weight and molecular weight distribution, of the polymer governs the properties of the resulting polyamide, which differ from those of conventional aliphatic polyamides. This biobased polyamide elastomer is a promising candidate to substitute some fossil fuel-based medium-hardness TPEs for applications, such as insulation, sealing, automotives, and construction.

After cellulose, lignin is the most commonly used natural polymer in green biomaterials. Pulp and paper mills and emerging cellulosic biorefineries are the main sources of technical lignin. However, only 2–5% of lignin has been converted into biomaterials. Making lignin-based polymer biocomposites to replace petroleum-based composites has piqued the interest of many researchers worldwide due to the positive environmental impact of traditional composites over time. In composite development, lignin is being used as a filler in commercial polymers to improve biodegradability and possibly lower production costs. As a natural polymer, lignin may have different properties depending on the isolation method and source, affecting polymer-based composites. The application has been affected by the characteristics of lignin and the uniform distribution of lignin in polymers. The review’s goal was to provide an overview of technical lignin extraction, properties, and its potential appropriate utilization. It was also planned to revisit the lignin-based composites’ preparation procedure as well as their composite characteristics. Solvent casting and extrusion methods are used to fabricate lignin from polymeric matrices such as polypropylene, epoxy, polyvinyl alcohol, polylactic acid, starch, wood fiber, natural rubber, and chitosan. Packaging, biomedical materials, automotive, advanced biocomposites, flame retardant, and other applications for lignin-based composites has existed. As a result, the technology is still being refined to increase the performance of lignin-based biocomposites in several applications. This review could assist explain lignin’s position as a composite additive, which could lead to more efficient processing and application strategies.

Polymers play a prominent role in daily lives; however, there is a growing concern on the depleting fossil resources triggering the research for sustainable alternatives. Here, novel wholly biobased nanocomposites are prepared from polyamide 36,36 (PA36,36) thermoplastic elastomer and cellulose nanocrystals (CNCs). Further, the influence of CNC addition and CNC loading on the morphological features, thermal and mechanical properties of PA36,36 is studied. The presence of CNC in PA36,36 affects the thermal degradation of PA36,36. The additions of 10 and 30 wt% CNCs to the PA36,36 improve the tensile strength and Young's modulus by up to 700% and 750% to 9.6 and 6.8 MPa, respectively, while still maintaining relatively high elongation at break values. The hardness of the polymer increases significantly after the inclusion of CNC. The PA36,36/CNC nanocomposites also show relatively good resilience when exposed to 100% strain. Overall, these biobased thermoplastic elastomer nanocomposites can be potential alternatives for some existing rubbers with low or medium hardness.