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The introduction of dynamic bonds capable of mediating self-healing in a fully cross-linked polychloroprene network can only occur if the reversible moieties are carried by the cross-linker itself or within the main polymer backbone. Conventional cross-linking is not suitable for such a purpose. In the present work, a method to develop a self-healable and recyclable polychloroprene rubber is presented. Dynamic disulfide bonds are introduced as part of the structure of a crosslinker (liquid polysulfide polymer, Thiokol LP3) coupled to the polymer backbone via thermally initiated thiol-ene reaction. The curing and kinetic parameters were determined by isothermal differential scanning calorimetry and by moving die rheometer analysis; tensile testing was carried to compare the tensile strength of cured compound, healed compounds and recycled compounds, while chemical analysis was conducted by surface X-ray Photoelectron Spectroscopy. Three formulations with increasing concentrations of Thiokol LP-3 were studied (2, 4, 6 phr), reaching a maximum ultimate tensile strength of 22.4 MPa and ultimate tensile strain of 16.2 with 2 phr of Thiokol LP-3, 11.7 MPa and 10.7 strain with 4 phr and 5.6 MPa and 7.3 strain with 6 phr. The best healing efficiencies were obtained after 24 h of healing at 80 °C, increasing with the concentration of Thiokol LP-3, reaching maximum values of 4.5% 4.4% 13.4% with 2 phr, 4 phr and 6 phr, respectively, while the highest recycling efficiency was obtained with 4 phr of Thiokol LP-3, reaching 11.2%. Full article

Commercial application of lithium–sulfur (Li–S) batteries is still greatly hampered by several issues, especially the shuttle effect of polysulfides. In this work, we proposed a simple but effective method to restrain the shuttle of the soluble polysulfides by adopting a novel binder of Thiokol in the sulfur cathode. Compared to the battery with conventional polyvinylidene fluoride (PVDF) binder, the initial discharge capacity for the battery with the Thiokol binder were increased by 42%, that is from 578 to 819 mAh/g, while the capacity after 200 cycles were increased by 201%, which is from 166 to 501 mAh/g. Besides, according to the rate capability test cycling from 0.1 to 1 C, the battery with the Thiokol binder still released a capacity amounting to 90.9% of the initial capacity, when the current density returned back to 0.1 C. Based on the UV–vis and ex situ XRD results, it is reasonably proposed that the reactions with polysulfides of the Thiokol help to restrain the shuttle effect of polysulfides. It is therefore suggested that the novel Thiokol binder holds promise for application in high-performance lithium–sulfur batteries. Full article