Research Focus

• Dynamic activators synthesized by catalytic chain transfer polymerization; 

• Applied in traditional sulfur curing system to enable vulcanised natural rubber/carbon black composites self-healable at room temperature; 

• The natural rubber formulations showed improved wet traction but with higher rolling resistance to a standard formulation; 

• These results point to an interesting direction for further research into the performance of self-healing composites in vehicle tire applications  and reprocessable. 

• Vulcanized NR is efficiently degraded to liquid rubber at 210 °C for 3 min.

• Manganese stearate reduces the apparent activation energy of oxidative degradation.

• Both main chains and crosslinks were broken during catalytic degradation process.

• The obtained liquid rubber contained carbonyls, ether linkages, and sulfoxide groups.

• Using a one-step click reaction at room temperature for 20 min, methyl-3-mercaptopropionate (M3M) was grafted to SBS and reached 95.2% of grafting ratios.

•  The resultant M3M–SBS has high mechanical strain of 1000%, a high relative permittivity of εr = 7.5 and a low tan δ = 0.03. When used in a dielectric actuator, it can provide 9.2% strain at an electric field of 39.5 MV m–1 and can also generate an energy density of 11 mJ g–1 from energy harvesting. 

• It self-heals from electrical and mechanical breakdown. 

• This work demonstrates a facile route to produce self-healing, high permittivity, and low dielectric loss elastomers for both actuation and energy harvesting, which is applicable to a wide range of diene elastomer systems. 

• The nucleophile substitution reaction via conventional solid-state rubber compounding processes provides a facile crosslinking and reinforcement strategy for halogen-containing polymers. 

• The dynamic ionic crosslinking networks spontaneously benefit electromechanical and self-healing properties of the dielectric elastomers. 

• Utilizing dynamic cross-linkers to tune the electromechanical properties of commodity elastomers.

• The reversibly cross-linked polymer networks allows the design of smart and sustainable dielectric elastomer devices. 

• A Peano-hydraulically amplified self-healing electrostatic actuator is constructed by innovatively integrating a bilayer polymer shell for combined favorable properties of high dielectric strength, dielectric permittivity, and elastic modulus. 

• Compared with a traditional single-layer shell actuator, the new bilayer actuator architecture generates an increased strain (164%) at 5 kV and improves load-bearing capability (620 mN) at 6 kV, thereby providing a significantly enhanced actuation performance 

We clarify the concepts of biodegradability and compostability in bioplastics, in particular commercial synthetic biopolyesters, which have increasing technical and economic importance, and discuss how macromolecular design, blending, and additives can be used to modify their compostability. Future trends on the uptake of compostable and biodegradable bioplastics are also discussed. 

• PGA/PBAT films containing a glycidyl cross-linker were blown-extruded via industrial-scale twin-screw extrusion

• The surface of the films was then chemically cross-linked using electron beam treatment (EBT) to impart excellent barrier properties.

• A dosage of 250 kGy EBT resulted in the film having an oxygen barrier permeation of 57.0–59.8 cm3 mm m–2 24 h–1 atm–1 and a water vapor permeation of 26.8 g m–2 24 h–1 while maintaining a high toughness of 75 MPa. 

• Ionogels are composed of ionic liquid confined in a polymer network.

• Vitrimer ionogel can be healed, welded and recycled for sustainable soft electronics.

• The ionogel has 300 % strain at break, low modulus and high conductivity.

• The self-healable ionogel was used as strain sensor, soft electrode, and ionic cable.

• Stress-oscillation phenomenon observed in several polymer systems but remains poorly understood.

• Cold drawn PET shows stress-oscillation with regular transparent and opaque bands.

• A thermal pulse (<10 °C) is linked to rapid stress relaxation and yielding.

• No stress-induced crystallization occurs in either transparent or opaque bands.

• Opacity arises due to axially elongated voids created during rapid yielding.