Effects of high-boiling-point additive 2-Bromonaphthalene on polymer solar cells fabricated in ambient air

High boiling point solvent additive, employed during the solution processing of active layer fabrications, impact the efficiency of bulk heterojunction polymer solar cells (PSC) by influencing the morphological of the active layer. The photovoltaic performances of the PSCs based on the donor of poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]-dithiophene-2,6-diyl-alt-3-fluoro-2-[(2 ethylhexyl)carbonyl] thieno[3,4-b]thiophene-4,6-diy (PTB7) and the acceptor of [6, 6]-phenyl-C71-butyric-acidmethyl-ester (PC₇₁BM) was optimized using 5 vol% high-boiling-point solvent additive of 2-Bromonaphthalene (BN). The optimized air-processed PSC based on PTB7:PC₇₁BM (1:1.5 w/w) with 5 vol% BN exhibited a power conversion efficiency of 7.01% with open-circuit voltage (V _oc) of 0.731 V, short-circuit current density (J _sc) of 13.79 mA cm^?2, and fill factor (FF) of 69.46%. The effects of the additive on photovoltaic performances were illustrated with atomic force microscopy and transmission electron microscope measurements. Our results indicate that the improved efficiency is due to the optimized PTB7/PC₇₁BM interpenetrating network and the enhanced absorption of the active layer using the BN as solvent additive.     

Effect on properties of PVDF-HFP based composite polymer electrolyte doped with nano-SiO2

Various kinds of nano-SiO₂ using different catalysts were obtained and characterized by scanning electron microscope (SEM) technique. The results showed that the nano-SiO₂ using NH₃·H₂O as catalyst presented the best morphology. Poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) based composite polymer electrolyte (CPE) membranes doped with different contents of nano-SiO₂ were prepared by phase inversion method. The as-prepared CPE membranes were immersed into 1.0 M LiPF₆-EC/DMC/EMC electrolytes for 0.5 h to be activated. The physicochemical and electrochemical properties of the CPEs were characterized by SEM, X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) techniques. The results indicate that the CPEs doped with 10 % nano-SiO₂ exhibit the best performance. SEM micrographs showed that the CPE membranes have uniform surface with abundant interconnected micro-pores, and the uptake ratio was up to 104.4 wt%. EIS and LSV analysis also showed that the ionic conductivity at room temperature and electrochemical stability window of the modified membrane can reach 3.372 mS cm^?1 and 4.7 V, respectively. The interfacial resistance R _i was 670 Ω cm^?2 in the first day, then increased to a stable value of about 850 Ω cm^?2 in 10 days storage at room temperature. The Li/As-fabricated CPEs/LiCoO₂ cell also showed good charge–discharge performance, which suggested that the prepared CPE membranes can be used as potential electrolytes for lithium ion batteries.     

Fluorene‐based copolymers with donor–acceptor units on the side chain and main chain: Synthesis and application in polymer solar cells

Two narrow band gap fluorene‐based copolymers with donor–acceptor (D–A) structure on the polymer side chain and/or main chain are synthesized by Pd‐catalyzed Stille coupling reactions. The two copolymers have excellent thermal stability. The effects of D–A structure on the main and side chains on the absorption and electrochemical properties are studied. The copolymer PF‐BTh‐DBT with D–A structure both on the main and side chains has broader and stronger absorption and narrower band gap than the copolymer PF‐BTh with only a pendent D–A structure. The power conversion efficiency of the assembled solar cell using PF‐BTh‐DBT as donor and PC₇₁BM as acceptor is 1.6% with open‐circuit voltage (V_oc) 0.84 V under simulated AM 1.5 G solar irradiation (100 mW/cm²). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3276–3281, 2013     

Novel wide band-gap polymer utilizing fused hetero-aromatic unit for efficient polymer solar cells and field-effect transistors

Novel wide band-gap polymer of PBTFT containing dibenzosexithiophene-alt-bithiophene backbone was designed and synthesized via the Stille cross-coupling reaction. This polymer exhibited good thermal stability, well coplanar backbone and a broad absorption band from 350 nm to 610 nm with a wide optical band-gap of 2.02 eV. The polymer solar cells (PSCs) based on the PBTFT:PC₇₁BM active layer showed the power conversion efficiency of 3.0% with an open circuit voltage of 0.70 V, a short-circuit current of 7.94 mA cm⁻² and a fill factor of 53.98% under the illumination of AM.1.5, 100 mW cm⁻². Holes mobility up to 0.028 cm² V⁻¹ s⁻¹ with an on-off ratio of 1.0 × 10⁶ was obtained in the PBTFT-based organic field-effect transistors (OFETs). Our work indicates that the dibenzosexithiophene-alt-bithiophene based copolymer can be efficiently applied in PSCs and OFETs.     

Synthesis, characterization, photoluminescent, and electroluminescent properties of poly(biphenylenevinylene-alt-methoxyoctyloxyphenylenevinylene)

Poly(biphenylenevinylene-alt-2-methoxy-5-octyloxy-1,4-phenylene-vinylene) (PBPV-alt-MOPPV) has been designed and synthesized by Wittig polymerization. Structure, thermal stability, optical, and electrochemical properties of the resulting copolymer were characterized by FT-IR, ¹H NMR, elemental analysis, GPC, DSC, TGA, UV–Vis, PL, EL, and CV. The copolymer possessed excellent solubility in common organic solvents and good thermal stability. The absorption maxima of copolymer in solution and thin film were at 440 and 450 nm, the PL maxima in solution and thin film were at 510 and 550 nm. The PLED (ITO/PEDOT: PSS (40 nm)/polymer (80 nm)/Ca (30 nm)/Al (150 nm) showed a yellowgreen light emission around 530 nm. The maximum brightness and luminescence efficiency reached up to 1,450 cd m^?2, 0.12 cd A^?1, and 0.06 lm w^?1, respectively.     

Ionic interactions and transport characteristics of a new polymer electrolyte system containing poly(propylene glycol) 4000 complexed with AgCF3SO3

The effect of concentration of AgCF₃SO₃ salt on the behavior of ionic transport within the polymer electrolyte system containing the polymer host poly(propylene glycol) of molecular weight 4000 (PPG4000) has been investigated in terms of spectroscopic and electrochemical properties. It is evident that the presence of well-defined interactions between the ether oxygens and silver cations arising due to the complexation of the silver salt with the polymer matrix has enabled the chosen polymer electrolyte system to possess the maximum room temperature (298 K) electrical conductivity of 9.4 × 10^?5 S cm^?1 in the case of the typical composition having the ether oxygen-to-metal ratio (O:M) of 4:1 and the lowest activation energy E _a of 0.46 eV for Ag⁺ ionic conduction.     

Enhancement of photovoltaic properties in supramolecular polymer networks featuring a solar cell main-chain polymer H-bonded with conjugated cross-linkers

Stille polymerization was employed to synthesize a low-band-gap (LBG) conjugated main-chain polymer PBTH consisting of bithiazole, dithieno[3,2-b:2′,3′-d]pyrroles (DTP), and pendent melamine derivatives. Novel supramolecular polymer networks PBTH/C and PBTH/F were developed by mixing proper molar amounts of polymer PBTH (containing melamine pendants) to be hydrogen-bonded (H-bonded) with complementary uracil-based conjugated cross-linkers C and F (i.e., containing two symmetrical uracil moieties connected with carbazole and fluorene units through triple bonds). The formation of multiple H-bonds between polymer PBTH and cross-linkers C or F was confirmed by FT-IR measurements. In contrast to polymer PBTH, the supramolecular design with multiple H-bonds can enhance the photovoltaic properties of polymer solar cell (PSC) devices containing H-bonded polymer networks PBTH/C and PBTH/F by tuning their light harvesting capabilities, HOMO energy levels, and crystallinities. Initially, the power conversion efficiency (PCE) values of PSC devices containing supramolecular polymer networks PBTH/C and PBTH/F as electron donors and [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM) as an electron acceptor (polymer:PC₇₀BM = 1:1 w/w) are found to be 0.97 and 0.68%, respectively, in contrast to 0.52% for polymer PBTH. The highest PCE value of 1.56% with a short-circuit current densities (J_sc) value of 7.16 mA/cm², a open circuit voltages (V_oc) value of 0.60 V, and a fill factor (FF) of 0.36 was further optimized in the PSC device containing a supramolecular polymer network PBTH/C as polymer:PC₇₀BM = 1:2 w/w. These results indicate that supramolecular design is an effective route towards better photovoltaic properties of V_oc, J_sc, and PCE values in polymer solar cells.     

New low bandgap conjugated polymer derived from 2, 7‐carbazole and 5, 6‐bis(octyloxy)‐4, 7‐di(thiophen‐2‐yl) benzothiadiazole: Synthesis and photovoltaic properties

To develop conjugated polymers with low bandgap, deep HOMO level, and good solubility, a new conjugated alternating copolymer PC‐DODTBT based on N‐9′‐heptadecanyl‐2,7‐carbazole and 5, 6‐bis(octyloxy)‐4,7‐di(thiophen‐2‐yl)benzothiadiazole was synthesized by Suzuki cross‐coupling polymerization reaction. The polymer reveals excellent solubility and thermal stability with the decomposition temperature (5% weight loss) of 327°C. The HOMO level of PC‐DODTBT is ‐5.11 eV, indicating that the polymer has relatively deep HOMO level. The hole mobility of PC‐DODTBT as deduced from SCLC method was found to be 2.03 × 10^?4 cm²/Versus Polymer solar cells (PSCs) based on the blends of PC‐DODTBT and [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) with a weight ratio of 1:2.5 were fabricated. Under AM 1.5 (AM, air mass), 100 mW/cm^?2 illumination, the devices were found to exhibit an open‐circuit voltage (V_oc) of 0.73 V, short‐circuit current density (J_sc) of 5.63 mA/cm^?2, and a power conversion efficiency (PCE) of 1.44%. This photovoltaic performance indicates that the copolymer is promising for polymer solar cells applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fuel cell performance of polymer electrolyte membrane based on hexafluorinated sulfonated poly(ether sulfone)

The potential-current fuel cell characteristics of membrane electrode assemblies (MEAs) using hexafluorinated sulfonated poly(ether sulfone) copolymer are compared to those of Nafion^® based MEAs in the case of proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC). The hexafluorinated copolymer with 60 mol% of monosulfonated comonomer based acid form membrane is chosen for this study due to its high proton conductivity, high thermal stability, low methanol permeability, and its insolubility in boiling water. The catalyst powder is directly coated on the membrane and the catalyst coated membrane is used to fabricate MEAs for both fuel cells. A current density of 530 mA cm^?2 at 0.6 V is obtained at 70 °C with H₂/air as the fuel and oxidant. The peak power density of 110 mW cm^?2 is obtained at 80 °C under specific DMFC operating conditions. Other electrochemical characteristics such as electrochemical impedance spectroscopy, cyclic voltammetry, and linear sweep voltammetry are also studied.     

Synthesis, characterization, and photovoltaic property of a low band gap polymer alternating dithienopyrrole and thienopyrroledione units

The lower the highest occupied molecular orbital (HOMO) energy level of the conjugated polymer is, the higher the open-circuit voltage (V_OC) of the obtained polymer solar cell (PSC) is. To achieve this goal, a new conjugated polymer (PDTPTPD) alternating dithienopyrrole (DTP) and thienopyrroledione (TPD) units was designed and synthesized by Stille coupling reaction. Through UV-vis absorption and cyclic voltammetry (CV) measurements, it was found that the resulting copolymer exhibited both a low optical band gap of 1.62 eV and a low HOMO energy level of −5.09 eV owing to the electronegativity of TPD moiety. Preliminary photovoltaic study disclosed that the PSC based on PDTPTPD:PCBM ([6,6]-phenyl-C₆₁ butyric acid methyl ester) blend showed a power conversion efficiency (PCE) of 1.9%, with a V_OC of 0.70 V, and a short circuit current (I_SC) of 6.97 mA/cm², suggesting that PDTPTPD is a promising photovoltaic polymer.     

Electrochemical copolymerization of carbazole and 2,2′:5′-2″ terthiophene: characterization and micro-capacitor application

In this paper, a copolymer of carbazole (Cz) and 2,2′:5′,2″-terthiophene (TTh) was electropolymerized in 0.1 M sodium perchlorate (NaClO₄)/acetonitrile (CH₃CN) on glassy carbon electrode. The optimum conditions of resulting homopolymers of Cz, TTh and copolymer of Cz and TTh in the initial feed ratio of [Cz]₀/[TTh]₀ = 1/10 were characterized by cyclic voltammetry, Fourier-transform infrared-attenuated total reflectance, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy. Morphological analysis of copolymer shows that a micro-spherical and web-like morphology was formed for copolymer at different initial feed ratios of [Cz]₀/[TTh]₀ = 1/2, 1/5 and 1/10. The capacitive behavior of the modified electrodes was defined via Nyquist, Bode-magnitude, and Bode-phase plots. The highest low-frequency capacitance (C _LF) was obtained as 4.11 mFcm^?2 in the initial feed ratio of [Cz]₀/[TTh]₀ = 1/10. Double-layer capacitance (C _dl) and phase angles (θ) were obtained for homopolymer and copolymer systems. The highest C _dl was obtained as 2.01 mFcm^?2 for the copolymer in the initial feed ratio of [Cz]₀/[TTh]₀ = 1/2. The highest phase angle of copolymer was obtained as θ = ~75° in the initial feed ratio of [Cz]₀/[TTh]₀ = 1/1. These capacitance results confirmed that films of copolymer Cz/TTh are promising materials for micro-capacitor applications.     

Enzyme immobilization in a photosensitive conducting polymer bearing azobenzene in the main chain

A new photosensitive and thermosensitive monomer, namely bis(4-(3-thienyl ethylene)-oxycarbonyl)diazobenzene (TDAZO), was synthesized. The photochemical and thermal cis–trans isomerization of the monomer has been investigated. The rate constants of the photoisomerization of TDAZO in ACN and DCM were 0.195 and 0.308 min^?1, respectively. For spectroelectrochemical investigation and enzyme immobilization application, TDAZO copolymerized with thiophene and pyrrole. Electrochemical and spectroelectrochemical properties of P(TDAZO-co-Th) were investigated and invertase was immobilized in P(TDAZO-co-Py) copolymer. Immobilization of enzymes was carried out by the entrapment of the enzyme in conducting polymer matrices during electrochemical polymerization of pyrrole through thiophene moieties of the TDAZO. Optimum conditions for this electrode, such as pH, temperature, kinetic parameters (K _m and V _max) and operational stability were investigated. Kinetic parameters invertase-immobilized in copolymer were smaller than free enzyme. The optimum operational temperature was 10 °C higher for immobilized enzyme than that of the free enzyme. Due to strong interaction between enzyme and diazo group in the polymer main chain, thermal, pH and operational stability of enzyme has been enhanced.     

Interpenetrating polymer networks based on polyurethane and organic-inorganic copolymer

The investigation of the features of the formation of interpenetrating polymer networks (IPNs) based on cross-linked polyurethane and organic-inorganic copolymer (OIC) based on hydroxyethyl methacrylate (HEMA) and titanium isopropoxide (Ti(OPrⁱ)₄) was carried out using the IR spectroscopy method. It has been demonstrated that during the synthesis of organic-inorganic IPNs (OI IPNs), three-dimensional cross-linked structures with the inclusion of (-TiO₂-) fragments in the polymer chain of poly(hydroxyethyl methacrylate) are formed. The examinations of the viscoelastic properties and thermal stability of organic-inorganic IPNs by dynamic mechanical (DMA) and thermogravimetric analysis (TGA) showed that the value of M _c decreases with an increase in the content of (-TiO₂-) fragments in OI IPN; in addition, the thermal stability of the obtained hybrid OI IPNs increases significantly compared to the parent systems.     

Performance of PVDF-HFP-based gel polymer electrolytes with different pore forming agents

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel polymer electrolytes (GPEs) with polyvinylpyrrolidone (PVP) and urea as a pore forming agent, respectively, were fabricated by phase inversion method. Physicochemical properties of the as-prepared polymer electrolytes were characterized by SEM, XRD, TG, electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). The results showed that the GPE membranes using urea as pore forming agent present a uniform surface with abundant interconnected micro-pores and possess upto 330?°C decomposition temperature; the XRD patterns indicate that adding urea into the polymer matrix can attain more amorphous areas than adding PVP; the reciprocal temperature dependence of ionic conductivity of as-prepared GPEs follows Vogel-Tamman-Fulcher relation and the ionic conductivity at room temperature is 2.212?mS cm^?1 for PVP pore forming GPEs and 2.823?mS cm^?1 for urea pore forming GPEs, respectively; the interfacial resistance of the Li/GPEs/Li cell using urea as pore forming agent can achieve a quick steady value of about 660??? cm^?1 lower than that of PVP of about 760??? cm^?1 during the same storage conditions; the electrochemical stability window of the GPEs with urea can be stable upto 5.0?V (vs. Li⁺/Li) at room temperature. The battery performance of the assembled Li/GPEs/LiCoO₂ coin cell also showed that the cell using urea as pore forming agent in GPEs demonstrated excellent first charge/discharge rate and cycle performances. These excellent physicochemical and battery properties indicated that urea can be used as a kind of excellent pore forming agent for polymer electrolytes in the lithium-ion polymer battery.     

Ion conducting nano-composite polymer electrolytes: synthesis and ion transport characterization

Synthesis and ion transport characterization of a new K⁺-ion conducting nano-composite polymer electrolytes (NCPEs): (1?x) [70PEO:30KBr] + x SiO₂, where 0 < x < 20 wt%, are reported. The present NCPEs have been cast using a novel hot-press technique in place of the traditional solution cast method. The conventional solid polymer electrolyte (SPE) composition: (70PEO:30KBr), identified as the highest conducting composition at room temperature, has been used as first-phase host matrix and nano-size (~8 nm) particles of SiO₂ as second-phase dispersoid. As a consequence of dispersal of SiO₂ in SPE host, two orders of conductivity enhancement have been observed in NCPE composition: [95(70PEO:30KBr) + 5SiO₂] and this has been referred to as optimum conducting composition (OCC). The polymer-salt/nano-filler SiO₂ complexation and thermal properties characterization were done with the help of XRD, FTIR, SEM, DSC and TGA studies. The ion transport behavior in NCPEs have been discussed on the basis of experimental measurements on some basic ionic parameters, viz. conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (t _ion), etc. The temperature-dependent conductivity studies of NCPE OCC have been done and activation energy (E _a) value was determined using log σ?1/T Arrhenius plot.     

Preparation of Sn‐doped CdS/TiO2/conducting polymer fiber composites for efficient photocatalytic hydrogen production under visible light irradiation

Sn‐doped CdS/TiO₂ heterojunction was synthesized on the conducting polymer fiber mat by hydrothermal method. The conducting polymer fiber mat was made by electrospinning from polyvinylidene fluoride, styrene‐maleic anhydride copolymer, and nano‐graphites as conducting fillers. The Sn‐doped CdS/TiO₂ heterojunction was characterized by XRD, XPS, SEM, TEM, TGA, and UV–Vis absorption spectra. Under simulated solar light irradiation, a combination of Sn‐doped CdS/TiO₂/conducting polymer was found to be highly efficient for photocatalytic hydrogen evolution from splitting of water. The photocatalytic hydrogen production efficiency was up to 2885 μmol h^?1 g^?1cat. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42300.     

Preparation of a PVA/HAP composite polymer membrane for a direct ethanol fuel cell (DEFC)

A novel PVA/Hydroxyapatite (HAP) composite polymer membrane was prepared by the direct blend process and solution casting method. The characteristic properties of the PVA/HAP composite polymer membranes were investigated using thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and the AC impedance method. An alkaline direct ethanol fuel cell, consisting of an air cathode with MnO₂ carbon inks based on Ni-foam, an anode with PtRu black on Ni-foam, and the PVA/HAP composite polymer membrane, was assembled and investigated. It was found that the alkaline direct ethanol fuel cell comprising of a novel cheap PVA/HAP composite polymer membrane showed an improved electrochemical performance in ambient temperature and air. As a result, the maximum power density of the alkaline DEFC, using a PtRu anode based on Ni-foam (10.74 mW cm⁻²), is higher than that of DEFC using an E-TEK PtRu anode based on carbon (7.56 mW cm⁻²) in an 8M KOH + 2M C₂H₅OH solution at ambient temperature and air. These PVA/HAP composite polymer membranes are a potential candidate for alkaline DEFC applications.     

Preparation and characterization of titanium dioxide core and polymer shell hybrid composite particles prepared by two-step dispersion polymerization

Titanium dioxide core and polymer shell composite poly (styrene-co-divinylbenzene)-methacrylic acid [P (St-co-DVB)-MAA]] particles were prepared by two-step dispersion polymerization. Fourier transform IR spectroscopy and elemental analysis were used to measure the content of methacrylic acid in composites particles. X-ray measurement photoelectron spectroscopy (XPS) measurements indicated the presence of an MAA unit on the surface of the composite particles. The combined results of the elemental analysis and the XPS measurements showed that the copolymer on the surface of poly (St-co-DVB)-MAA composite particles was rich in MAA compared with that in the interior of the composite particles. Field-emission scanning electron microscopy (FE-SEM) was used to study the morphology characterization. The composite particles produced showing good spectral reflectance compare with bare TiO₂. TGA results indicated that the encapsulation efficiency and estimated density of composite particles. Encapsulation of TiO₂ was up to 87.4% and the density was ranged from 1.78 to 2.06 g/cm³. Estimated density of the composite particles is suitable to 1.73 g/cm³, due to density matching with suspending fluid.     

A quaternized poly(vinyl alcohol)/chitosan composite alkaline polymer electrolyte: preparation and characterization of the membrane

Quaternized poly(vinyl alcohol)/chitosan (QPVA/CS) composite membranes were prepared by solution casting method with AlCl₃·6H₂O aqueous solution as solvent for CS and glutaraldehyde as a crosslinker. The crystalline, thermal and mechanical properties of the QPVA/CS composite membranes were studied by Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, thermogravimetry and tensile test measurements, respectively. The composite membranes were immersed in potassium hydroxide aqueous solution to form polymer electrolyte membranes. The alkaline uptake, swelling ratio, ion conductivity and methanol permeability of the electrolyte membranes were studied. The experimental results indicated that aluminum chloride hexahydrate (AlCl₃·6H₂O) had a positive effect on the mechanical properties of the QPVA/CS composite membrane. The elongation-at-break of this membrane reached the maximum of 401.0%. The alkaline uptake and swelling ratio of the composite membranes decreased. With the addition of 30 wt% AlCl₃·6H₂O, the composite membrane showed the ion conductivity and methanol permeability of 1.82 × 10^?2 S cm^?1 and 2.17 × 10^?6 cm² s^?1, respectively. These values were higher than those of the membrane with acetic acid as the solvent for CS. The selectivity of the QPVA/CS membrane could reach 8.39 × 10³ S s cm^?3. This study showed that with AlCl₃·6H₂O as the solution for CS, the high performance QPVA/CS composite alkaline polymer electrolyte membrane could be prepared.     

Composite polymer electrolytes based on the low crosslinked copolymer of linear and hyperbranched polyurethanes

Low crosslinked copolymer of linear and hyperbranched polyurethane (CHPU) was prepared, and the ionic conductivities and thermal properties of the composite polymer electrolytes composed of CHPU and LiClO₄ were investigated. The FTIR and Raman spectra analysis indicated that the polyurethane copolymer could dissolve more lithium salt than the corresponding polymer electrolytes of the non crosslinked hyperbranched polyurethane, and showed higher conductivities. At salt concentration EO/Li = 4, the electrolyte CHPU30‐LiClO₄ reached its maximum conductivity, 1.51 × 10^?5 S cm^?1 at 25°C. DSC measurement was also used for the analysis of the thermal properties of polymer electrolytes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3607–3613, 2007