Effect of poly(ethylene glycol) on the solid‐state polymerization of poly(ethylene terephthalate)

Poly(ethylene glycol) (PEG) and end‐capped poly(ethylene glycol) (poly(ethylene glycol) dimethyl ether (PEGDME)) of number average molecular weight 1000 g mol^?1 was melt blended with poly(ethylene terephthalate) (PET) oligomer. NMR, DSC and WAXS techniques characterized the structure and morphology of the blends. Both these samples show reduction in T_g and similar crystallization behavior. Solid‐state polymerization (SSP) was performed on these blend samples using Sb₂O₃ as catalyst under reduced pressure at temperatures below the melting point of the samples. Inherent viscosity data indicate that for the blend sample with PEG there is enhancement of SSP rate, while for the sample with PEGDME the SSP rate is suppressed. NMR data showed that PEG is incorporated into the PET chain, while PEGDME does not react with PET. Copyright © 2005 Society of Chemical Industry     

Biodegradability of poly(ethylene terephthalate) copolymers with poly(ethylene glycol)s and poly(tetramethylene glycol)

Poly(ethylene terephthalate) copolymers were prepared by melt polycondensation of dimethyl terephthalate and excess ethylene glycol with 10–40mol% (in feed) of poly(ethylene glycol) (E) and poly(tetramethylene glycol) (B), with molecular weight (MW) of E and B 200–7500 and 1000, respectively. The reduced specific viscosity of copolymers increased with increasing MW and content of polyglycol comonomer. The temperature of melting (T_m), cold crystallization and glass transition (T_g) decreased with the copolymerization. T_m depression of copolymers suggested that the E series copolymers are the block type at higher content of the comonomer. T_g was decreased below room temperature by the copolymerization, which affected the crystallinity and the density of copolymer films. Water absorption increased with increasing content of comonomer, and the increase was much higher for E1000 series films than B1000 series films. The biodegradability was estimated by weight loss of copolymer films in buffer solution with and without a lipase at 37°C. The weight loss was enhanced a little by the presence of a lipase, and increased abruptly at higher comonomer content, which was correlated to the water absorption and the concentration of ester linkages between PET and PEG segments. The weight loss of B series films was much lower than that of E series films. The abrupt increase of the weight loss by alkaline hydrolysis is almost consistent with that by biodegradation.     

Direct Synthesis of ZSM-5 and Mordenite Using Poly(ethylene glycol) as a Structure-Directing Agent

ZSM-5 (SiO₂/Al₂O₃ = 55) and mordenite (SiO₂/Al₂O₃ = 48) were synthesized directly using poly(ethylene glycol) (PEG 200) as a structure-directing agent. The PEG 200 molecules were occluded in the pores of ZSM-5 but not in mordenite. It is expected that the formation of ZSM-5 occurs via a layered phase such as magadiite.     

Encapsulation of curcumin by methoxy poly(ethylene glycol‐b‐aromatic anhydride) micelles

Suitable carrier systems for sustained release of curcumin were studied by using the self‐assembled polymeric micelles. Poly(ethylene glycol) methyl ether and poly(aromatic anhydride) were used as the hydrophilic and hydrophobic blocks, respectively, in forming amphiphilic diblock copolymers. Four different types of polymers methoxy poly(ethylene glycol‐ b‐1,3‐bis(p‐carboxyphenoxy)propane) (mPEG₅₀₀₀CPP, mPEG₂₀₀₀CPP), methoxy poly(ethylene glycol‐b‐1,6‐bis(p‐carboxyphenoxy)hexane) (mPEG₅₀₀₀CPH, mPEG₂₀₀₀CPH) were synthesized via melt condensation approach. Micelles were formed at very low polymer concentration with stable hydrophobic cores. The particle sizes of micelles remained stable during degradation period. All four different polymeric micelles showed low cytotoxicity toward human fibroblasts cells and can kill cancer cells in very low concentrations. High loading efficiency and drug content were observed in curcumin‐loaded micelles. Curcumin showed mild initial burst (30% of drug loading in the first 24 h) when released from the micelles and its release was sustained for at least 18 days. These micelles, especially those of mPEG₅₀₀₀CPP, show potential to serve as the delivery vehicles for sustained release of curcumin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Synthesis and characterization of a novel stimuli‐responsive magnetite nanohydrogel based on poly(ethylene glycol) and poly(N‐isopropylacrylamide) as drug carrier

A novel stimuli‐responsive magnetite nanohydrogel (MNHG), namely [poly(ethylene glycol)‐block‐poly(N‐isopropylacrylamide‐co‐maleic anhydride)₂]‐graft‐poly(ethylene glycol)/Fe₃O₄ [PEG‐b‐(PNIPAAm‐co‐PMA)₂]‐g‐PEG/Fe₃O₄, was successfully developed. For this purpose, NIPAAm and MA monomers were block copolymerized onto PEG‐based macroinitiator through atom transfer radical polymerization technique to produce PEG‐b‐(PNIPAAm‐co‐PMA)₂. The synthesized Y‐shaped terpolymer was crosslinked through the esterification of maleic anhydride units using PEG chains to afford a hydrogel. Afterward, magnetite nanoparticles were incorporated into the synthesized hydrogel through the physical interactions. The chemical structures of all synthesized samples were characterized using Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. Morphology, thermal stability, size, and magnetic properties of the synthesized MNHG were investigated. In addition, the doxorubicin hydrochloride loading and encapsulation efficiencies as well as stimuli‐responsive drug release ability of the synthesized MNHG were also evaluated. The drug‐loaded MNHG at physiological condition exhibited negligible drug release values. In contrast, at acidic (pH 5.3) condition and a little bit higher temperature (41 °C) the developed MNHG showed higher drug release values, which qualified it for cancer chemotherapy due to especial physiology of cancerous tissue in comparison with the surrounding normal tissue. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46657.     

Synthesis and characterization of novel block copolymer from trans‐4‐hydroxy‐L‐proline and poly(ethylene glycol)

A series of novel ABA‐type block copolymers were synthesized by polymerization of trans‐4‐hydroxy‐L ‐proline (HyP) in the presence of various molecular weight poly(ethylene glycol)s (PEGs), a bifunctional OH‐terminated PEG using stannous octoate as catalyst. The optimal reaction conditions for the synthesis of the copolymers were obtained with 5 wt % stannous octoate at 140°C under vacuum (20 mmHg) for 24 h. The synthesized copolymers were characterized by IR spectroohotometry, proton nuclear magnetic resonance, differential scanning calorimetry, and Ubbelohde viscometer. The glass transition temperature (T_g) of the copolymers shifted to significantly higher temperature with increasing the number average degree of polymerization and HyP/PEO molar ratio. In contrast, the melting temperature (T_m) decreased with increasing the HyP/PEO molar ratio. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1581–1587, 2001     

Influence of a pore-forming agent on swelling,network parameters,and permeability of poly(ethylene glycol)-crosslinked poly(methyl vinyl ether-co-maleic acid) hydrogels: Application in transdermal delivery systems

We characterized hydrogels, prepared from aqueous blends of poly(methyl vinyl ether-co-maleic acid) (PMVE/MA) and poly(ethylene glycol) (PEG 10,000 Daltons) containing a pore-forming agent (sodium bicarbonate, NaHCO₃). Increase in NaHCO₃ content increased the equilibrium water content (EWC) and average molecular weight between crosslinks (M_c) of hydrogels. For example, the %EWC was 731, 860, 1109, and 7536% and the M_c was 8.26, 31.64, 30.04, and 3010.00 × 10⁵ g/mol for hydrogels prepared from aqueous blends containing 0, 1, 2, and 5% w/w of NaHCO₃, respectively. Increase in NaHCO₃ content also resulted in increased permeation of insulin. After 24 h, percentage permeation was 0.94, 3.68, and 25.71% across hydrogel membranes prepared from aqueous blends containing 0, 2, and 5% w/w of NaHCO₃, respectively. Hydrogels containing the pore-forming agent were fabricated into microneedles (MNs) for transdermal drug delivery applications by integrating the MNs with insulin-loaded patches. It was observed that the mean amount of insulin permeating across neonatal porcine skin in vitro was 20.62% and 52.48% from hydrogel MNs prepared from aqueous blends containing 0 and 5% w/w of NaHCO₃. We believe that these pore-forming hydrogels are likely to prove extremely useful for applications in transdermal drug delivery of biomolecules. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of pH and Neutral Salts on the Adsorption of the Poly(ethylene glycol terephthalate) Condensates Toward Poly(ethylene terephthalate) Fiber

This study deals with the effects of pH and neutral salts on the adsorption of PET fiber with four kinds of poly(ethylene glycol terephthalate) condensated from dimethyl terephthalate (DMT) and poly(ethylene glycol) (PEG). The surface properties of the aqueous solution, the contact angle of polyol‐treated PET fabrics, and its parameters were also discussed. The pH of the solution or the adding of neutral salt in the polyol solution largely affected the contact angle of polyol‐treated PET fabrics as well as the surface tension of the solution. A lower pH of the polyol solution or adding neutral salts in the solution showed a lower surface tension and a lower contact angle that resulted in a better adsorption between polyol and poly(ethylene terephthalate) fibers. The lower pH of the solutions and a higher valence of the added neutral salt in the solution showed a largely positive effect on the adsorption parameters, and the order of effectiveness is Al₂(SO₄)₃ > MgSO₄ > Na₂SO₄.     

Lithium ionic conductivity in poly(ether urethanes) derived from poly(ethylene glycol) and lysine ethyl ester

Poly(ether urethanes) obtained by the copolymerization of poly(ethylene glycol) (PEG) and lysine ethyl ester (LysOEt) are elastomeric materials that can be processed readily to form flexible, soft films. In view of these desirable physicomechanical properties, the potential use of these new materials as solid polymer electrolytes was explored. Solid polymer electrolytes were prepared with copolymers containing PEG blocks of different lengths and with different concentrations of lithium triflate (LiCF₃SO₃). Correlations between the length of the PEG block, the concentration of lithium triflate in the formulation, and the observed Li⁺ ion conductivity were investigated. Solid electrolyte formulations were characterized by differential scanning calorimetry for glass transition temperatures (T_g), melting points (T_m), and crystallinity. Ionic conductivity measurements were carried out on thin films of the polymer electrolytes that had been cast on a microelectrode assembly using conventional ac-impedance spectroscopy. These polymer electrolytes showed inherently high ionic conductivity at room temperature. The optimum concentration of lithium triflate was about 25–30% (w/w), resulting at room temperature in an ionic conductivity of about 10⁻⁵ S cm⁻¹. For poly(PEG₂₀₀₀-LysOEt) containing 30% of LiCF₃SO₃, the activation energy was ∼ 1.1 eV. Our results indicate that block copolymers of PEG and lysine ethyl ester are promising candidates for the development of polymeric, solvent-free electrolytes. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1449–1456, 1997     

ABA triblock copolymers from poly(p‐dioxanone) and poly(ethylene glycol)

Poly(p‐dioxanone)–poly(ethylene glycol)–poly(p‐dioxanone) ABA triblock copolymers (PEDO) were synthesized by ring‐opening polymerization from p‐dioxanone using poly(ethylene glycol) (PEG) with different molecular weights as macroinitiators in N₂ atmosphere. The copolymer was characterized by ¹H NMR spectroscope. The thermal behavior, crystallization, and thermal stability of these copolymers were investigated by differential scanning calorimetry and thermogravimetric measurements. The water absorption of these copolymers was also measured. The results indicated that the content and length of PEG chain have a greater effect on the properties of copolymers. This kind of biodegradable copolymer will find a potential application in biomedical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1092–1097, 2006     

Poly(Caprolactone)‐Poly(N‐Isopropyl Acrylamide)‐Fe3O4 Magnetic Nanofibrous Structure with Stimuli Responsive Drug Release

Poly(caprolactone; PCL)—poly(N‐isopropylacrylamie; PNIPAAm)—Fe₃O₄ fiber, that can be magnetically actuated, is reported. Here, a structure is engineered that can be utilized as a smart carrier for the release of chemotherapeutic drug via magneto‐thermal activation, with the aid of magnetic nanoparticles (MNPs). The magnetic measurement of the fibers revealed saturation magnetization values within the range of 1.2–2.2 emu g^?1. The magnetic PCL‐PNIPAAm‐Fe₃O₄ scaffold shows a specific loss power value of 4.19 W g^?1 at 20 wt% MNPs. A temperature increase of 40 °C led to a 600% swelling after only 3 h. Doxorubicin (DOX) as a model drug, demonstrates a controllable drug release profile. 39% ± 0.92 of the total drug loaded is released after 96 h at 37 °C, while 25% drug release in 3 h at 40 °C is detected. Cytotoxicity results show no significant difference in cell attachment efficiency between the MNP‐loaded fibers and control while the DOX‐loaded fibers effectively inhibited cell proliferation at 24 h matching the drug release profile. The noncytotoxic effect, coupled with the magneto‐thermal property and controlled drug release, renders excellent potential for these fibers to be used as a smart drug‐release agent for localized cancer therapy.     

Relationship between the crystallization behavior of poly(ethylene glycol) and stereocomplex crystallization of poly(L‐lactic acid)/poly(D‐lactic acid)

Poly(l ‐lactic acid) (PLLA) is a good biomedical polymer material with wide applications. The addition of poly(ethylene glycol) (PEG) as a plasticizer and the formation of stereocomplex crystals (SCs) have been proved to be effective methods for improving the crystallization of PLLA, which will promote its heat resistance. In this work, the crystallization behavior of PEG and PLLA/poly(d ‐lactic acid) (PDLA) in PLLA/PDLA/PEG and PEG‐b‐PLLA/PEG‐b‐PDLA blends has been investigated using differential scanning calorimetry, polarized optical microscopy and X‐ray diffraction. Both SCs and homocrystals (HCs) were observed in blends with asymmetric mass ratio of PLLA/PDLA, while exclusively SCs were observed in blends with approximately equal mass ratio of PLLA/PDLA. The crystallization of PEG was only observed for the symmetric blends of PLLA_39k/PDLA_35k/PEG_2k, PLLA_39k/PDLA_35k/PEG_5k, PLLA_69k/PDLA_96k/PEG_5k and PEG‐b‐PLLA_31k/PEG‐b‐PDLA_27k, where the mass ratio of PLLA/PDLA was approximately 1/1. The results demonstrated that the formation of exclusively SCs would facilitate the crystallization of PEG, while the existence of both HCs and SCs could restrict the crystallization of PEG. The crystallization of PEG is related to the crystallinity of PLLA and PDLA, which will be promoted by the formation of SCs. © 2017 Society of Chemical Industry     

Poly(ethylene glycol)s catalyzed two-phase dehydrochlorination of poly(vinyl chloride) with potassium hydroxide

Poly(ethylene glycol)s [HO(CH₂CH₂O)_nH, where n > 3] are highly active and selective in catalyzing dehydrochlorination of poly(vinyl chloride) in organic–aqueous hydroxide two-phase systems. Their catalytic activity and stability are much higher than those of widely used quaternary ammonium or phosphonium compounds. Poly(vinyl chloride) can be extensively dehydrochlorinated within half an hour at room temperature. The products are polyacetylene-like and have long polyene sequences according to their UV/visible, FT-Raman, and FT-infrared spectra. They can be doped by iodine to conductive states, with conductivities of 1–4 S cm⁻¹. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2463–2469, 1998     

Determination of monomer reactivity ratios for copolymerizations of methacrylic acid with poly (ethylene glycol) monomethacrylate

Self-associating copolymers of methacrylic acid (MAA) with poly (ethylene glycol) monomethacrylate (PEGMA) were prepared by free radical copolymerization of MAA with PEGMA using dispersion polymerization in D₂O, or solution polymerization in a 50/50 ethanol–D₂O mixture. These copolymers have been studied as components of reversible hydrogels¹ and in medical applications.² In order to understand the relationship between the copolymer structure and its performance, it is important to determine the sequence distribution of the copolymer. The copolymer architecture is determined by the reactivity ratios and integrated instantaneous feed compositions. The reactivity ratios were determined using the first-order Markov method³ by running a series of reactions at various initial monomer ratios and determining the monomer incorporation into the copolymer as a function of time, via ¹H nuclear magnetic resonance. The reactivity ratios for dispersion copolymerizations of MAA with PEGMA in water were determined to be r₁ = 1.03 and r₂ = 1.02, whereas solution copolymerization in 50/50 EtOH–H₂O gave reactivity ratios of r₁ = 2.0 and r₂ = 3.6. These results show that the reactivity ratios and copolymer architecture are influenced by the solvent system. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1019–1025, 1998     

Solution thermodynamics of poly(ethylene glycol)/water systems

The unperturbed molecular dimensions of poly(ethylene glycol) (PEG) samples (of different molecular weights) have been evaluated in aqueous solutions from viscosity measurements at 25, 30, 35, and 40°C. The unperturbed dimension, K_θ, has been determined from extrapolation methods, i.e., Kurata–Stockmayer–Fixman (KSF), Inagaki–Suzuki–Kurata (ISK), and Berry equations. The hydrodynamic expansion factor, α_η, as well as the unperturbed root‐mean‐square end‐to‐end distance, 〈r²〉, found for the system indicated that the polymer coils contract as the temperature is raised from 25 to 40°C. The long‐range interaction (excluded volume) parameter, B, was also evaluated and a significant decrease was found for the PEG/water system between 25 and 40°C. The theta temperatures, θ, were obtained from the temperature dependence of (1/2 ? χ) and the second virial coefficient was detected in the temperature interval of 25–40°C for the system and quite a good agreement with the calculated values evaluated via extrapolation and interpolation methods was observed. The thermodynamic interaction parameter χ was evaluated through the sum of the individual values of enthalpy and entropy dilution parameters, χ_H and χ_S, for PEG samples. All the unperturbed molecular dimensions of PEG/water system were calculated and compared according to M _w and M _n values of PEG samples. Calculated values were interpreted mainly on the basis of hydrogen‐bond formation between polymer segments and PEG‐water molecules in solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 203–216, 2006     

Decomposition of poly(ethylene glycol) in nanocomposites

Poly(ethylene glycol) (PEG) has been widely used in studies of polymer–clay nanocomposites because it readily intercalates in smectite clays. Nanocomposites were formed from PEG with molecular weights (M_w) ranging from 300 to 20,000, as evidenced by expansion of the basal planar spacing of the clay (d₀₀₁) in X‐ray diffraction. However PEG with high molecular weight (≥ 10,000) readily underwent degradation during preparation of composites when heated at low temperature (60°C) due to oxidative attack. Molecular weight distribution determined by gel permeation chromatography showed that this degradation always happened with or without the presence of clay and it became more serious when the molecular weight was higher. The reduction in pH of aqueous PEG solutions after degradation increased with molecular weight. Since d₀₀₁ was independent of molecular weight over a wide range, such degradation cannot be detected by this method. Precautions against oxidative attack are therefore recommended to avoid decomposition when preparing PEG–clay nanocomposites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 548–552, 2004     

The adsorption behaviors of the multiple stimulus‐responsive poly(ethylene glycol)‐based hydrogels for removal of RhB dye

In this article, the multiple stimulus‐responsive organic/inorganic hybrid hydrogels by combining poly(2‐(2‐methoxyethoxy) ethyl methacrylate‐co‐oligo (ethylene glycol) methacrylate‐co‐acrylic acid) (PMOA) hydrogel with magnetic attapulgite/Fe₃O₄ (AT‐Fe₃O₄) nanoparticles were applied to the removal of Rhodamine B (RhB) dye from wastewater. The adsorption of RhB by the hydrogels was carried out under different external environmental, such as pH, temperature and magnetic‐field. The results showed that the hydrogels still possessed temperature, pH and magnetic‐field sensitivity during the adsorption process, which indicated that the adsorption could be controlled by the hydrogels responsive. The dye adsorption had a significant increment at 30°C and the removal of RhB could reach to over 95%. Besides, the low pH values were also favorable for the RhB adsorption, the removal was over 90% at pH = 4.56. Kinetic studies showed that the pseudo‐second order kinetic model well fitted the experimental data. The rate constant of adsorption was 0.0379 g/mg min. Langmuir and Freundlich isotherm models were applied to the equilibrium adsorption for describing the interaction between sorbent and adsorbate. The maximum K_L and K_F were 2.23 (L/g) and 0.87 (mg/g) at 30°C, respectively. Under the external magnetic‐field, the adsorption rate significantly increased within 250 min and the hydrogels could be separated easily from wastewater. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42244.     

Crystallization kinetics of poly(1,4‐butylene‐co‐ethylene terephthalate)

The crystallization kinetics of poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET), and their copolymers poly(1,4‐butylene‐co‐ethylene terephthalate) (PBET) containing 70/30, 65/35 and 60/40 molar ratios of 1,4‐butanediol/ethylene glycol were investigated using differential scanning calorimetry (DSC) at crystallization temperatures (T_c) which were 35–90 °C below equilibrium melting temperature . Although these copolymers contain both monomers in high proportion, DSC data revealed for copolymer crystallization behaviour. The reason for such copolymers being able to crystallize could be due to the similar chemical structures of 1,4‐butanediol and ethylene glycol. DSC results for isothermal crystallization revealed that random copolymers had a lower degree of crystallinity and lower crystallite growth rate than those of homopolymers. DSC heating scans, after completion of isothermal crystallization, showed triple melting endotherms for all these polyesters, similar to those of other polymers as reported in the literature. The crystallization isotherms followed the Avrami equation with an exponent n of 2–2.5 for PET and 2.5–3.0 for PBT and PBETs. Analyses of the Lauritzen–Hoffman equation for DSC isothermal crystallization data revealed that PBT and PET had higher growth rate constant G_o, and nucleation constant K_g than those of PBET copolymers. © 2001 Society of Chemical Industry     

Microstructure and crystallization of melt‐mixed poly(ethylene terephthalate)/poly(ethylene isophthalate) blends

Physical blends of poly(ethylene terephthalate) (PET) and poly(ethylene isophthalate) (PEI), abbreviated PET/PEI (80/20) blends, and of PET and a random poly(ethylene terephthalate‐co‐isophthalate) copolymer containing 40% ethylene isophthalate (PET₆₀I₄₀), abbreviated PET/PET₆₀I₄₀ (50/50) blends, were melt‐mixed at 270°C for different reactive blending times to give a series of copolymers containing 20 mol % of ethylene isophthalic units with different degrees of randomness. ¹³C‐NMR spectroscopy precisely determined the microstructure of the blends. The thermal and mechanical properties of the blends were evaluated by DSC and tensile assays, and the obtained results were compared with those obtained for PET and a statistically random PETI copolymer with the same composition. The microstructure of the blends gradually changed from a physical blend into a block copolymer, and finally into a random copolymer with the advance of transreaction time. The melting temperature and enthalpy of the blends decreased with the progress of melt‐mixing. Isothermal crystallization studies carried out on molten samples revealed the same trend for the crystallization rate. The effect of reaction time on crystallizability was more pronounced in the case of the PET/PET₆₀I₄₀ (50/50) blends. The Young's modulus of the melt‐mixed blends was comparable to that of PET, whereas the maximum tensile stress decreased with respect to that of PET. All blend samples showed a noticeable brittleness. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3076–3086, 2003     

Polymer electrolytes based on poly(ethylene glycol) and cyanoresin

Polymer electrolytes based on a mixed polymer matrix consisting of poly(ethylene glycol) (PEG) and cyanoresins with lithium salt and plasticizer were prepared with an in situ blending process to improve both the mechanical properties and the ionic conductivity (σ). The PEG/lithium perchlorate (LiClO₄) complexes, including blends of cyanoethyl pullulan (CRS) and cyanoethyl poly(vinyl alcohol) (CRV), exhibited higher σ's than a simple PEG/LiClO₄ complex when the blend compositions of CRS/CRV were 5 : 5 or 3 : 7 or than CRV alone. When the CRS/CRV blend was compared with a copolymer of cyanoethyl pullulan and cyanoethyl poly(vinyl alcohol) (CRM) in the same molar ratio, the σ values of the polymer electrolytes containing the CRM copolymer series were slightly higher than those of the CRS/CRV blends containing PEG/LiClO₄ complexes. Moreover, the addition of cyanoresin to PEG/LiClO₄/(ethylene carbonate–propylene carbonate) polymer electrolytes provided better thermal stability and dynamic mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2402–2408, 2007