Solid polymer electrolytes. IV. Preparation and characterization of novel crosslinked epoxy‐siloxane polymer complexes as polymer electrolytes

Abstract

Two series of novel crosslinked siloxane‐based polymers and their complexes with lithium perchlorate (LiClO4) were prepared and characterized by Fourier transform infrared spectroscopy, solid‐state NMR (13C, 29Si, and 7Li nuclei), and differential scanning calorimetry. Their thermal stability and ionic conductivity of these complexes were also investigated by thermogravimetric and AC impedance measurements. In these polymer networks, poly(propylene oxide) chains with different molecular weights were introduced through self‐synthesized epoxy‐siloxane precursors cured with two curing agents. The glass‐transition temperature (Tg) of these copolymers is dependent on the length of the ether units. The dissolution of LiClO4 considerably increases the Tg of the polyether segments. The dependence of the ionic conductivity was investigated as a function of temperature, LiClO4 concentration, and the molecular weight of the polyether segments. The ion‐transport behavior was affected by the combination of the ionic mobility and number of carrier ions. The 7Li solid‐state NMR line shapes of these polymer complexes suggest a significant interaction between Li+ ions and the polymer matrix, and temperature‐ and LiClO4 concentration‐dependent chemical shifts are correlated with ionic conductivity. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1226–1235, 2002

Preparation, thermal properties, and flame retardance of epoxy–silica hybrid resins

“…Therefore, flame retardants with especially high efficiency are attractive because the amounts of the flame retardants used in the resin compositions can be reduced and, consequently, the harm to the properties of the epoxy resins can also be reduced. Effective approaches have been reported to provide epoxy resins satisfying the aforementioned requirements 4–15. One attractive approach is using flame retardants exhibiting the phosphorus–silicon synergism of flame retardance 7–12.…”

Insulin‐like growth factor‐1 receptor and phosphorylated AKT‐serine 473 expression in 132 resected thymomas and thymic carcinomas

“…As evidenced from Figure 1, it is obvious that as the concentration of LiClO 4 salt in the composite polymer complexes increases, the frequencies and intensities of the characteristic bands change significantly, indicating that introduction of the salt in the composite electrolytes can change the intermolecular interactions. In addition, a further hydroxyl stretching vibration is detected around 3250 cm −1 for each composite electrolytes, which can be ascribed to the OH stretching vibration of the hydroxyls hydrogen‐bonded to OH groups 29…”

Solid polymer electrolytes. VII. Preparation and ionic conductivity of gelled polymer electrolytes based on poly(ethylene glycol) diglycidyl ether cured with α,ω‐diamino poly(propylene oxide)

“…This was attributed to the longer PPO segment possessing a higher fraction of the free volume of the polymer electrolyte network; this enabled easier ionic transportation and agreed with our previous work on epoxy-siloxane polymer networks complexed with LiClO 4 . 15 Because the D2000 oligomer had a higher molecular weight than the D400 oligomer, with the same composition, the polymer electrolyte network with D2000 as a curing agent had a lower crosslinking degree (i.e., a higher fraction of the free volume) than the network with D400.…”