Synergistic effects in cross-linked blends of ion-conducting PEO-/PPO-based unsaturated polyesters

Abstract

Ion-conductive unsaturated polyesters (UP) were synthesised from poly(ethylene oxide) (Xn = 9, 13, 22, 90) or poly(propylene oxide) (Xn = 7, 13, 20, 34, 68) and maleic anhydride. Subsequently, the polyesters were doped with LiClO4 and cross-linked with styrene using a redox initiator. For PEO-based polyesters, the minimum resistivity is found at an O/Li+ molar ratio of 50/1. In contrast, more lithium is required to reach the minimum when using PPO (O/Li+ = 10/1). Unlike the PEO-based polyesters, cross-linking of the PPO types gives rise to decreasing resistivities at increasing molecular weight. This correlates well with the transverse proton relaxation time determined by single-sided NMR, which is an indicator of the chain mobility. The cross-linking reaction of these UP with styrene exactly follows the predictions based on the copolymerisation parameters and is, therefore, not dependent on the ratio of styrene to UP double bonds as previously reported. Due to the opposing effects of the molecular weight on the ion conductivity of PEO- and PPO-based UP, 1:1 blends of short-chain PPO and long-chain PEO polyesters were cross-linked with styrene. The resulting networks showed a resistivity of 4 kΩ m (σ = 2.5∙10−4 S∙m−1), which is 5 times lower than the pure PEO and 3 times lower than the pure PPO materials.

Thermally responsive polymers for overcoming thermal runaway in high-safety electrochemical storage devices

“…Moreover, copolymers based on PNIPAM usually require complex synthesis processes, which limit their practical application in electrochemical devices. 98,106,107 PEO/PPO-based polymers. Pluronics (triblock PEO-PPO-PEO copolymers) are important sol-gel transition polymers.…”

“…In recent years, the gelation mechanism of PEO-PPO-PEO block copolymers in aqueous solutions has been studied in depth. [106][107][108][109] Although PPO and PEO have the same main chain structure, PPO has poor compatibility with water due to steric hindrance of its side methyl groups, resulting in phase separation in PPO aqueous solutions at very low temperatures. In contrast, PEO is hydrophilic.…”

“…Despite the advantages of Pluronic polymers, they are usually utilized in high concentrations of above 30%, which limits their ionic conductivity at room temperature. [107][108][109]112,113 Cellulose derivatives. PNIPAM-based and Pluronic solgel thermoresponsive electrolytes have been extensively studied.…”

“…Moreover, copolymers based on PNIPAM usually require complex synthesis processes, which limit their practical application in electrochemical devices. 98,106,107…”

Preparation A Cross-Linked Copolymer By Using Unsaturated Poly(2-Butene Maleate) Polyester and Methyl Methacrylate

“…They are generally produced by the condensation of a diol with anhydrides. The obtained condensation products form very durable structures and coatings when cross-linked with vinyl monomers such as methyl methacrylate, styrene [5][6][7]. The mechanical and chemical properties of the cross-linked resin depend on the types and amounts of anhydrides and diols used.…”