Anhydrous proton conducting polymer electrolytes based on polymeric ionic liquids

Imidazolium types of ionic liquids were immobilized by tethering it to acrylate backbone. These imidazolium salt containing acrylate monomers were polymerize at 70oC by free radical polymerization to give polymers poly(AcIm-n) with n being the side chain lenght. The chemical structure of the polymer electrolytes obtained by the described synthetic routes was investigated by NMR-spectroscopy. The polymers were doped with various amounts of H3PO4 and LiN(SO2CF3)2, to obtain poly(AcIm-n) x H3PO4 and poly(AcIm-2-Li) x LiN(SO2CF3)2. The TG curves show that the polymer electrolytes are thermally stable up to about 200◦C. DSC results indicates the softening effect of the length of the spacers (n) as well as phosphoric acid. The proton conductivity of the samples increase with x and reaches to 10-2 Scm-1 at 120oC for both poly(AcIm-2)2H3PO4 and poly(AcIm-6)2H3PO4. It was observed that the lithium ion conductivity of the poly(AcIm-2-Li) x LiN(SO2CF3)2 increases with blends (x) up to certain composition and then leveled off independently from blend content. The conductivity reaches to about 10-5 S cm-1 at 30oC and 10-3 at 100oC for poly(AcIm-2-Li) x LiN(SO2CF3)2 where x is 10. The phosphate and phosphoric acid functionality in the resulting polymers, poly(AcIm-n) x H3PO4, undergoes condensation leading to the formation of cross-linked materials at elevated temperature which may improve the mechanical properties to be used as membrane materials in fuel cells. High resolution nuclear magnetic resonance (NMR) spectroscopy was used to obtain information about hydrogen bonding in solids. The low Tg enhances molecular mobility and this leads to better resolved resonances in both the backbone region and side chain region. The mobile and immobile protons can be distinguished by comparing 1H MAS and 1H-DQF NMR spectra. The interaction of the protons which may contribute to the conductivity is observed from the 2D double quantum correlation (DQC) spectra

Anhydrous proton conducting polymer electrolytes based on polymeric ionic liquids

Imidazolium types of ionic liquids were immobilized by tethering it to acrylate backbone. These imidazolium salt containing acrylate monomers were polymerize at 70oC by free radical polymerization to give polymers poly(AcIm-n) with n being the side chain lenght. The chemical structure of the polymer electrolytes obtained by the described synthetic routes was investigated by NMR-spectroscopy. The polymers were doped with various amounts of H3PO4 and LiN(SO2CF3)2, to obtain poly(AcIm-n) x H3PO4 and poly(AcIm-2-Li) x LiN(SO2CF3)2. The TG curves show that the polymer electrolytes are thermally stable up to about 200◦C. DSC results indicates the softening effect of the length of the spacers (n) as well as phosphoric acid. The proton conductivity of the samples increase with x and reaches to 10-2 Scm-1 at 120oC for both poly(AcIm-2)2H3PO4 and poly(AcIm-6)2H3PO4. It was observed that the lithium ion conductivity of the poly(AcIm-2-Li) x LiN(SO2CF3)2 increases with blends (x) up to certain composition and then leveled off independently from blend content. The conductivity reaches to about 10-5 S cm-1 at 30oC and 10-3 at 100oC for poly(AcIm-2-Li) x LiN(SO2CF3)2 where x is 10. The phosphate and phosphoric acid functionality in the resulting polymers, poly(AcIm-n) x H3PO4, undergoes condensation leading to the formation of cross-linked materials at elevated temperature which may improve the mechanical properties to be used as membrane materials in fuel cells. High resolution nuclear magnetic resonance (NMR) spectroscopy was used to obtain information about hydrogen bonding in solids. The low Tg enhances molecular mobility and this leads to better resolved resonances in both the backbone region and side chain region. The mobile and immobile protons can be distinguished by comparing 1H MAS and 1H-DQF NMR spectra. The interaction of the protons which may contribute to the conductivity is observed from the 2D double quantum correlation (DQC) spectra

Polysulfide-ene polymerization of bisacrylamides and bismaleimides toward sulphur-rich polymers

Given the ever-increasing importance of developing more sustainable solutions for the fabrication and engineering of polymeric materials, alternative building blocks to the petroleum-derived chemicals are gaining growing interest. In addition to its natural abundance, elemental sulfur is produced industrially in vast quantities which is primarily obtained as a side product from oil refineries and gas purification plants. Thus, elemental sulfur has been prospected as a sustainable resource for the fabrication of structurally diverse polymers. In this study an efficient methodology to obtain sulfur-rich polymers from elemental sulfur-derived polysulfide salts is reported. Polysulfide-ene step growth polymerization of bisacrylamide and bismaleimide-based monomers with bifunctional disodium pentasulfide (Na2S5) generated structurally diverse polyamide and polyimide copolymers incorporating polysulfide chains on the polymer backbones. Copolymers up to 31.8 kDa molecular weight (Mn) and 94% monomerconversions were efficiently obtained under ambient temperature conditions and without the need of any metal or organo-catalyst. By choosing various bifunctional ene monomers, structurally diverse and tailorable linear copolymers were obtained. The methodology was also extended to the fabrication of sulfur-rich crosslinked polymers by employing a multifunctional thiolate-based crosslinker. As a potential application, fabricated crosslinked polymers were employed as adsorbents to remove toxic mercury ions from water. The reported synthetic strategy demonstrated the efficiency of polysulfide-ene reaction to synthesize sulfur-rich polyamide and polyimide polymers and could broaden the available polymerization reaction tools that employelemental sulfur-derived polysulfide salts in functional polymer synthesis.</p

Inorganic–organic polymer electrolytes based on poly(vinyl alcohol) and borane/poly(ethylene glycol) monomethyl ether for Li-ion batteries

In this study, poly(vinyl alcohol) (PVA) was modified with poly(ethylene glycol) monomethyl ether (PEGME) using borane-tetrahydrofuran (BH3/THF) complex. Molecular weights of both PVA and PEGME were varied prior to reaction. Boron containing comb-branched copolymers were produced and abbreviated as PVA1PEGMEX and PVA2PEGMEX. Then polymer electrolytes were successfully prepared by doping of the host matrix with CF3SO3Li at several stoichiomeric ratios with respect to EO to Li. The materials were characterized via nuclear magnetic resonance (H-1 NMR and B-11 NMR). Fourier transform infrared spectroscopy (FT-IR). Thermogravimetry (TG) and differential scanning calorimeter (DSC). The ionic conductivity of these novel polymer electrolytes were studied by dielectric-impedance spectroscopy. Li-ion conductivity of these polymer electrolytes depends on the length of the side units as well as the doping ratio. Such electrolytes possess satisfactory ambient temperature ionic conductivity (>10(-4) Scm(-1)). Cyclic voltammetry results illustrated that the electrochemical stability domain extends over 4V. (C) Elsevier B.V. All rights reserved

Synthesis, conductivity and magnetic properties of poly(N-pyrrole phosphonic acid)–Fe3O4 nanocomposite

The present study describes the preparation and characterization of poly(N-pyrrole phosphonic acid)-Fe3O4 (PPP/Fe3O4-NPs) nanocomposite. Structural characterizations and some physical properties such as magnetism, ac-dc conductivity performance and dielectric permittivity of the nanocomposite were performed by FT-IR. XRD, TGA, TEM and VSM (vibrating sample magnetometer). FT-IR measurements of the nanocomposite showed that the Fe3O4-NPs bound to the polymer chains via phosphonic acid moieties. From the XRD powder pattern, the crystallite size was estimated as 11 +/- 4 nm which is consistent with the TEM micrographs and magnetic core size from VSM measurements. Analysis of conductivity and permittivity meausurements revealed the magnetic transition above 60 which gives rise to the maximum conductivity of 1.7 x 10(-6) S cm(-1) at 100 degrees C. (C) 2011 Elsevier B.V. All rights reserved