6. Dynamic rheological frequency analysis of poly(sulfur-r-1,3diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) copolymers 7. Dynamic mechanical Analysis of of poly(sulfur-r-1,3diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) copolymers 8. Time resolved rheological analysis of self-healing properties of poly(sulfur-r-1,3-diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5-triisopropenylbenzene) (poly(S-r-TIB)) 9. Mechanical analysis of poly(sulfur-r-1,3-diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5-triisopropenylbenzene) (poly(S-r-TIB)) copolymers 10. Plot of refractive Index as a function of wavelength for poly(sulfur-r-1,3,5-triisopropenylbenzene) (poly(S-r-TIB)) copolymers 11. FTIR and UV-Vis transmission plots of poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) copolymers 12. Differential scanning calorimetry (DSC) analysis of poly(sulfur-r-1,3diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) copolymers 13. Thermogravimetric analysis (TGA) of poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) and poly(sulfur-r-1,3diisopropenylbenzene) (poly(S-r-DIB))copolymers II) Results and Discussion Section A. Dynamic rheological frequency analysis of poly(sulfur-r-1,3diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5triisopropenylbenzene) (poly(S-r-TIB)) copolymers to determine degree of crosslinked network microstructures B. Time resolved rheological analysis of self-healing properties of poly(sulfur-r-1,3-diisopropenylbenzene) (poly(S-r-DIB)) and poly(sulfur-r-1,3,5-triisopropenylbenzene) (poly(S-r-TIB)) copolymers C. Powder X-Ray Diffraction (XRD) of poly(sulfur-r-TIB) copolymers

The practical implementation of Li-S technology has been hindered by short cycle life and poor rate capability owing to deleterious effects resulting from the varied solubilities of different Li polysulfide redox products. Here, we report the preparation and utilization of composites with a sulfur-rich matrix and molybdenum disulfide (MoS2) particulate inclusions as Li-S cathode materials with the capability to mitigate the dissolution of the Li polysulfide redox products via the MoS2 inclusions acting as "polysulfide anchors". In situ composite formation was completed via a facile, one-pot method with commercially available starting materials. The composites were afforded by first dispersing MoS2 directly in liquid elemental sulfur (S8) with sequential polymerization of the sulfur phase via thermal ring opening polymerization or copolymerization via inverse vulcanization. For the practical utility of this system to be highlighted, it was demonstrated that the composite formation methodology was amenable to larger scale processes with composites easily prepared in 100 g batches. Cathodes fabricated with the high sulfur content composites as the active material afforded Li-S cells that exhibited extended cycle lifetimes of up to 1000 cycles with low capacity decay (0.07% per cycle) and demonstrated exceptional rate capability with the delivery of reversible capacity up to 500 mAh/g at 5 C.

High mechanical strength, thermal stability, and flame retardancy are three crucial criteria for highperformance polymers to be suitable for aerospace applications. Most polymers, however, cannot meet the three criteria simultaneously. Herein, phosphonium bromide-terminated poly(ether imide)s (PEI-PhPPh 3 Br) simultaneously possessing high mechanical strength, thermal stability, and flame retardancy were synthesized by functionalizing dianhydrideterminated poly(ether imide)s (PEI-DA) with triphenyl-4aminophenylphosphonium bromide. With the judiciously designed end group, PEI-PhPPh 3 Br exhibited excellent tensile properties, thermal stability, and flame retardancy. Importantly, PEI-PhPPh 3 Br with a molecular weight of 12 kDa [PEI-PhPPh 3 Br (12k)] showed a tensile strength of 109 ± 4 MPa and a Young's modulus of 2.75 ± 0.12 GPa, much higher than those of the noncharged PEI analogue. Additionally, PEI-PhPPh 3 Br (12k) showed outstanding flame retardancy, better than the state-of-the-art commercial PEIs, as evidenced by the high limiting oxygen index of 51% and high char yield of 60% at 980 °C. The study herein provides a highly effective strategy to simultaneously improve mechanical strength, thermal stability, and flame retardancy, which are three important properties rarely possessed by most polymers.

The glass transition temperature, thermal degradation temperature, and complex viscosity of metal sulfonated polyetherimides decrease with an increase in metal cation size.