Optimization of X-Ray Computerized Tomography for Polymer Materials

Since polymers mainly consist of the light atomic elements, the transmission of polymers against X-rays is usually too high to be visualized in X-ray microscopy, and hence it has been considered that polymers are not suitable for X-ray computerized tomography (XCT). We calculate the X-ray absorption coefficients of various polymers and find reasonably good conditions for the XCT observations of polymers: the use of 15 KeV X-rays on average can resolve the polystyrene (PS) and poly (methymethacrylate) (PMMA) in 3 µm spatial resolutions. According to this calculation, we build an XCT and experimentally confirm the visualization of the phase-separation structures of PS/PMMA blends.     

Microstructural characterization of AP40 apatite-wollastonite glass-ceramic

The microstructure of an apatite-wollastonite (code name AP40) glass-ceramic is analyzed in this study by combining 2D microscopy, phase analysis, X-ray absorption and synchrotron X-ray refraction computed tomography (XCT and SXRCT, respectively). It is shown that this combination provides a useful toolbox to characterize the global microstructure in a wide scale range, from sub-micrometer to millimeter. The material displays a complex microstructure comprising a glassy matrix with embedded fluorapatite and wollastonite small crystals. In this matrix, large (up to 200 μm) spike-shaped structures are distributed. Such microstructural features are oriented around a central sphere, thereby forming a structure resembling a sea urchin. A unique feature of SXRCT, in contrast to XCT, is that internal interfaces are visualized; this allows one to show the 3D distribution of these urchins with exceptionally good contrast. Furthermore, it is revealed that the spike-shaped structures are not single crystals, but rather composed of sub-micrometric crystals, which are identified as fluorapatite and diopside phases by SEM-EDX analysis.     

A new processable donor–acceptor polymer displaying neutral state yellow electrochromism

We report here the synthesis of a new solution processable neutral state yellow polymeric electrochromic material containing 2,5-bis-dithienyl-1H-pyrrole (SNS)-donor and 1,8 naphthalimide-acceptor (SNS–NI) as a subunit. The electrochemical and optical properties were investigated via cyclic voltammetry (CV), UV–Vis absorption and fluorescence emission measurements, respectively. Besides, electrochromic performance of poly(SNS–NI) has been compared to the both the film preparation method and poly(1-phenyl-2,5-dithiophen-2-ylpyrrole) [poly(SNS–P)] as a standard polymer. In the poly(SNS–NI), yellow color of the polymer film at neutral state converted to green and then dark blue upon the polymer film fully oxidized in the positive regime. SNS–NI polymer film prepared via spin casting process exhibits a high contrast ratio in the near-IR region (ΔT% = 56% at 890 nm), a response time of about 1 s, high coloration efficiency (299 cm² C⁻¹) and retained its performance by 98.6% even after 5000 cycles. Finally, the results clearly indicate that both electronic nature of the molecule and film preparation method have a major impact on electrochromic performance of these polymers.     

Studies on the interactions of CO2 with biodegradable poly(dl-lactic acid) and poly(lactic acid-co-glycolic acid) copolymers using high pressure ATR-IR and high pressure rheology

Amorphous poly(dl-lactic acid) (P_dlLA) and poly(lactic acid-co-glycolic acid) (PLGA) polymers have been used to fabricate porous scaffolds for tissue engineering applications via a supercritical foaming technique. The chemical composition of the polymers and the morphology (pore size, porosity and interconnectivity) of the scaffolds are crucial because they influence cell filtration, migration, nutrient exchange, degradation and drug release rate. To control the morphology of supercritical foamed scaffolds, it is essential to study the interactions of polymers with CO₂ and the consequent solubility of CO₂ in the polymers, as well as the viscosity of the plasticized polymers. In this paper, we are showing for the first time that well known and useful biodegradable polymers can be plasticized easily using high pressure CO₂ and that we can monitor this process easily via a high pressure attenuated total reflection Fourier transform infrared (ATR-IR) and rheology. High pressure ATR-IR has been developed to investigate the interactions of CO₂ with P_dlLA and PLGA polymers with the glycolic acid (GA) content in the copolymers as 15, 25, 35 and 50% respectively. Shifts and intensity changes of IR absorption bands of the polymers in the carbonyl region (∼1750 cm⁻¹) are indicative of the interaction on a qualitative level. A high pressure parallel plate rheometer has also been developed for the shear viscosity measurements of the CO₂-plastisized polymers at a temperature below their glass transition temperatures. The results demonstrate that the viscosities of the CO₂-plasticized polymers at 35 °C and 100 bar were comparable to the values for the polymer melts at 140 °C, demonstrating a significant process advantage through use of scCO₂. The data from the high pressure rheology and high pressure ATR-IR, combined with the sorption and swelling studies reported previously, demonstrate that the interaction and the solubility of CO₂ in PLGA copolymers is related to the glycolic acid content. As the glycolic acid ratio increases the interaction and consequent solubility of CO₂ decreases. The potential applications of this study are very broad, from tissue engineering and drug delivery to much broader applications with other polymers in areas that may range from composites and polymer synthesis through to injection moulding.     

Physical,optical and gamma radiation shielding competence of newly boro-tellurite based glasses: TeO2–B2O3–ZnO–Li2O3–Bi2O3

Herein, a traditional melt quenching method was utilized to synthesize glasses with a nominal chemical composition (80-x)TeO₂-xB₂O₃–5ZnO–5Li₂O₃–10Bi₂O₃: 30≤ x ≤ 80 mol%). The produced sample was coded as TBBZL30 to TBBZL80. X-ray diffraction (XRD) has been employed to test the amorphous nature of the synthesized samples. In the range of 200–500 nm wavelength, UV–Vis spectra for the glasses have been performed. Optical energy gaps ($E_{gap}$) have been determined based on the absorption measurements. With the help of ($E_{gap}$), refractive index (n), molar polarizability (α^M), metallization criterion (M^Cri.), molar refractivity (R^M), static dielectric constant (ε^Sta.), optical dielectric constant (ε^Opt.), reflection loss (R^L) and optical transmission (T^Opt.) have been calculated. For the fabricated boro-tellurite glasses, Phy-X/PSD was used to report some shielding factors for several energies between 15 keV and 15 MeV. The maximum attenuation for all samples took place at 15 keV and the mass attenuation coefficient varied between 52.309 and 57.084 cm²/g. The linear attenuation coefficient (LAC) results demonstrated that TBBZL80 has the highest attenuation than the rest of samples which is due to high content of TeO₂ (containing 80 mol% of TeO₂) whereas TBBZL30 has the lowest attenuation. The LAC for the fabricated samples varied between 230.160 and 351.064 cm-¹ at 15 keV. The minimum effective atomic number (EAN) occurred between 0.8 and 4 MeV and varied between 15.16 and 17.35 for TBBZL30 and 25.10–28.33 for TBBZL80. The addition of TeO₂ was found to enhance the EAN and improved shielding properties for the tested TBBZL glass systems.     

Neutral state colorless electrochromic polymer networks: Spacer effect on electrochromic performance

A series of carbazole-based monomers and their corresponding polymers with various spacer units were synthesized and coated onto ITO-glass surface via an electrochemical cross-linking process. All carbazole-based polymers exhibited multi-electrochromic behavior thanks to two separate oxidation processes. All materials were characterized by FT-IR, ¹H NMR, GPC, DSC, UV–vis, Florescence and CV. In addition, electrochromic properties of the cross-linked polymer films were investigated via spectro-electrochemical measurements. The colorless films were converted to yellowish green and greenish blue colors at the anodic regime. The results indicate that the spacer unit between the carbazole unit and the polymer backbone has a great impact on the optical and electrochemical properties and also on the electrochromic performance of these polymers. PVBEC with benzyloxy based spacer exhibits a high contrast ratio (ΔT% = 55 at 690 nm), a faster response time of about 2.1 s, a higher coloration efficiency (331 cm² C⁻¹) and a better stability (retains its performance by 94.3% even after 1000 cycles).     

Synthesis and properties of novel aromatic polyamides with non-conjugated bichromophoric units in the main chains

A dicarboxylic acid bearing two cinnamic acids units linked in their para positions by a methylene bridge was synthesized by the reaction of 4,4′-methylene-bis(benzaldehyde) and malonic acid, characterized by spectral and elemental analysis and used to prepare a series of novel photocrosslinkable aromatic polyamides through its reaction with various ether-bridged aromatic diamines. ¹H and ¹³C NMR, IR and UV spectroscopy confirmed the structure of the monomer and photopolymers. The resulting polymers with inherent viscosities of 0.65–1.14 dL/g were soluble in polar aprotic solvents, such as DMF, DMSO, DMAc and NMP, and showed good film-forming properties. Their weight-average and number-average molecular weights, determined by GPC (polystyrene standard), were in the range 57,400–84,300 and 24,000–40,900, respectively. The percent of water absorbed at 65% relative humidity varied between 1.57% and 2.35%. The polyamides exhibited glass transition temperatures between 202 and 239 °C, and they were stable up to a temperature of 350 °C in air. Wide-angle X-ray scattering diagrams did not show any crystalline reflection and no endothermic peak attributable to polymer melting was observed in DSC curves of the polymers. These photosensitive polymers exhibited strong UV absorption maxima both in solution and film state, and displayed three photochemical transformations under the UV exposure, viz. a trans-cis isomerization, favored in the early stage of UV irradiation, a bimolecular cyclodimerization, leading to the generation of a cyclobutane ring, and a photo-Fries rearrangement evidenced only in polymer solutions.     

Modifications in the structural,morphological, optical properties of Ag45Se40Te15 thin films by proton ion irradiation for optoelectronics and nonlinear applications

This current work reports the 30 keV proton ion irradiation induced structural, morphological, and optical properties change in Ag₄₅Se₄₀Te₁₅ films at different fluences. The thin films were irradiated with different ion fluences, such as 5 × 10¹⁵ ions/cm²,1 × 10¹⁶ ions/cm² and 5 × 10¹⁶ ions/cm². The electronic loss (S_e) dominates over the nuclear loss (S_n) in proton irradiation. The X-ray diffraction study shows the phase transformation from amorphous to crystalline upon ion irradiation. The Raman analysis confirms the change in chemical and vibrational bonds due to structural alterations in the films. The surface morphology has been studied by field emission scanning electron microscopy and the composition of the films has been checked by the energy dispersive X-ray analysis. The particle size increased upon the increase in ion irradiation fluence. The surface roughness of the films has been studied by atomic force microscopy. The transmission data is used to calculate the linear optical parameters. The absorption edge shifts towards the high wavelength region inferring the reduction in the optical bandgap. The linear refractive index of the films increased with ion fluence. The optical density increased at the high wavelength region while the skin depth decreased with fluence. The carrier concentration per effective mass decreased while the plasma frequency increased with proton irradiation. The nonlinearity (χ ⁽³⁾ and n₂) values increased significantly with the increase in fluences. Such kind of materials with optimization in their optical parameters are primarily essential for cutting-edge photonic, optoelectronic, and nonlinear optical applications.     

Donor-acceptor copolymer based on dioctylporphyrin: Synthesis and application in organic field-effect transistors

A novel alternating D–A copolymer, PPor–BT, with dioctylporphyrin (Por) as a donor unit and 5,6-bis(octyloxy)benzo-2,1,3-thiadiazole (BT) as an acceptor unit, was designed and synthesized by Pd-catalyzed Sonogashira-coupling reaction. The copolymer showed good solubility and film-forming ability. PPor–BT exhibited a broad absorption band from 350 to 950 nm with two peaks centered at 456 and 818 nm corresponding to the Soret band and Q-bands absorption of porphyrin segments, respectively. The employment of electron deficient BT unit to construct donor-acceptor structure observably broadened the absorption spectrum and enhanced the Q-band absorption of the porphyrin-based polymer. The HOMO and LUMO energy levels of the polymer are ?5.06 eV and ?3.63 eV, respectively. The solution-processed organic field-effect transistors (OFETs) were fabricated with bottom gate/top-contact geometry. The mobility of PPor–BT based OFEFs reached 4.3 × 10^?5 cm² V^?1 s^?1 with an on/off current ratio of 10⁴. This mobility is among the highest values for porphyrin-based polymers.     

Synthesis and charge carrier mobility of a solution-processable conjugated copolymer based on cyclopenta[c]thiophene

A new polymer comprising alternate thiophene and didodecyloxymethyl substituted cyclopenta[c]thiophene unit, PDCPTT, was synthesized by the Stille coupling reaction and characterized by ¹H NMR, GPC, TGA, DSC, XRD, UV-vis absorption spectroscopy, photoluminescence spectroscopy and cyclic voltammetry. The copolymer is readily soluble in tetrahydrofuran, chloroform and toluene at ambient conditions and exhibits good thermal stability as it does not exhibit noteworthy weight loss until ∼300 °C under nitrogen. This polymer possesses a broad absorption band ranging at 400-650 nm (with an optical band gap of 1.90 eV). The DFT calculation predicts the polymer to be planar and the calculated band gap is only 0.17 eV higher than the experimentally determined band gap. Didodecyloxymethyl-3,4-cyclopentane substitution on alternate thiophene in a polythiophene, hitherto unexplored, showed an effective polymer based field effect transport characteristics; exhibiting hole mobility ≈1.4 × 10⁻² cm² V⁻¹ s⁻¹.     

Pneumatic impact ignition of selected polymers in high‐pressure oxygen environments

One likely cause of polymer ignition in high‐pressure oxygen systems is adiabatic‐compression heating of polymers, caused by pneumatic impact. This study investigates ignition by pneumatic impact of selected polymers in high‐pressure oxygen environments. Six polymers commonly used in high‐pressure oxygen systems were tested in a pneumatic‐impact test system at 8.3–37.9 MPa oxygen pressures. The six polymers tested were Teflon^®(polytetrafluoroethylene), Neoflon^®(polychlorotrifluoroethylene), PEEK (polyetheretherketone), Zytel^® 42 (Nylon 6/6), Buna N (nitrile rubber), and Viton^® A (copolymer of vinylidene fluoride and hexafluoropropylene). This study shows that the ignition of polymers due to pneumatic impact could be initiated by a local heterogeneous reaction between the hot oxygen and the oxidation sites of the polymer, and proposes an ignition mechanism. Ignition susceptibility of a material to the pneumatic impact can be expressed by its ignition probability. The ignition probabilities of the six polymers at the various oxygen pressures are presented. There is no good correlation between the ignition probability and the autoignition temperature. Copyright © 2006 John Wiley & Sons, Ltd.     

Assessment of flaws in cold-sintered ZnO via acoustic wave speed and attenuation measurements

The cold sintering process (CSP) is a low temperature processing technique that utilizes a transient phase to synthesize dense ceramics. However, some CSP parts contain microflaws that arise due to inhomogeneities in pressure, temperature, and transient phase. This work uses 20 MHz ultrasound to verify the presence of defects in CSP ZnO samples of varying densities (84%–97%). Acoustic metrics used in this work include wave speed, which is affected by differences in the effective elastic properties of the medium, and attenuation, which quantifies wave energy loss due to scattering from defects. Wave speed maps were inhomogeneous, suggesting density gradients which were verified with scanning electron microscopy. In addition, it was demonstrated that the pores produced by cold sintering are anisometric, which increases the anisotropy in the elastic properties. High attenuation regions (>300 Np/m) are present in all samples independent of relative density and correspond to defects identified in X-ray computed tomography (XCT) which were as small as 38 µm in effective diameter. However, some high attenuation spots do not correspond to visible defects in XCT, which suggests the presence of features undetectable with XCT such as residual secondary phases at the grain boundaries.     

Synthesis of poly[2]catenane having rigid linkage by 1,3-dipolar cycloaddition of diazido[2]catenane with 4,4′-diethynylbiphenyl

A novel poly[2]catenane having rigid triazole rings between [2]catenane moieties was synthesized by the 1,3-dipolar cycloaddition of diazido[2]catenane with 4,4′-diethynylbiphenyl. The reaction proceeded effectively under mild conditions and gave a polymer in high yield. The number average molecular weight (M_n) of the polymers was 1.5 × 10⁴-2.5 × 10⁴. A cyclic dimer consisting of two [2]catenane moieties and two biphenylene units was formed along with the polymer. The cyclodimerization was suppressed by performing the reaction at a low temperature without lowering the yield or molecular weight of the polymer. The novel poly[2]catenane had higher solubility in some solvents than the corresponding non-catenated polymer having a similar primary structure.     

Complete characterisation of BN fibres obtained from a new polyborylborazine

A new polymer was prepared at room temperature from a di-chloroborazine and a reactive aminoborane. It displays borazine rings unambiguously linked through three atoms N–B–N bridges. This connecting mode was evidence by ¹⁵N solid state NMR. This polyborazine was processed into a continuous polymer fibre of about 21 μm diameter, which was subsequently heat-treated under NH₃/N₂ up to 1800 °C for conversion into BN fibres. The achievement of hexagonal boron nitride was confirmed by X-ray diffraction and Raman spectroscopy. Tensile tests were carried out on the ceramic fibres. The average tensile strength is about 1000 MPa and the Young's modulus is close to 200 GPa. Structural characterisation of the BN fibres was undertaken by polarised light and transmission electronic microscopies.     

Synthesis and photovoltaic properties of alternative copolymers of benzo[1,2-b:4,5-b′]dithiophene and thiophene

Two conjugated polymers containing benzodithiophene (BDT) unit and the unit of thiophene or thieno[3,2-b]thiophene, P(BDT-T) and P(BDT-TT), were synthesized by Pd-catalyzed Stille coupling method. The UV–Vis absorption, thermal, and electrochemical properties of the two polymers were characterized. Photovoltaic properties of the polymers were studied by using the polymers as donor and PC₇₀BM as acceptor with a weight ratio of polymer: PC₇₀BM of 1:1.5. The power conversion efficiencies of the PSC devices based on P(BDT-T) reached 2.05% with an open-circuit voltage of 0.75 V, a short-circuit current of 4.5 mA cm⁻², and a fill factor of 0.61, under the illumination of AM1.5, 100 mW cm⁻².     

Novel green light-emitting polyfluorenes containing dibenzothiophene-S,S-dioxide-arylamine derivatives

Green light-emitting polyfluorenes were synthesized by Suzuki polycondensation via introducing dibenzothiophene-S,S-dioxide-(di-)tri-phenylamine (G₁ and G₂) moieties and dibenzothiophene-S,S-dioxide (SO) unit into the polyfluorene backbone, respectively. PF–SO–G copolymers show a high thermal stability and a moderate photoluminescence quantum yield in the range of 20–40%. The lowest unoccupied molecular orbital (LUMO) levels reduce with increasing the content of SO unit in the polymers. The efficient energy transfer from fluorene segment to G₁ or G₂ unit occurred in the PL process, and the EL emission peaked at about 510 nm was exclusively from G₁ or G₂ unit. Incorporating SO unit into the polymer backbone makes the device performances improved. The maximal luminous efficiency of 9.0 cd A^?1 with the CIE coordinates of (0.27, 0.56) was obtained for PF–SO15-G₂5 based on a single-layered device of ITO/PEDOT:PSS/polymer/CsF/Al. And the polymers (PF–SO15-G5)s exhibited a dramatic LE stability at high current densities, even though at the current density of 200 mA cm^?2, the luminous efficiencies only dropped 10%. SO unit lowers the LUMO level, balances the injection and transportation of both electron and hole in the polymers, and therefore improves the device performances. The hole- and electron-only devices show that the hole and electron flux are well balanced, which demonstrates that (PF-SO15-G5)s are bipolar polymers with a balanced charge carrier transport.     

Atomic scale characterization of the conformational dynamics of a thermo-sensitive and a non-thermo-sensitive oligomer using vibrational spectra obtained from molecular dynamics

Molecular dynamics simulations (MD) are used to calculate the vibrational spectra of a thermo-sensitive oligomer, namely, poly(N-isopropylacrylamide) (PNIPAM) and a non-thermo-sensitive oligomer, namely, poly(acrylamide) (PAAM) and characterize the atomic scale conformations. Despite the structural similarity between the two polymers, the response of PNIPAM and PAAM to a thermal stimulus is widely different; a coil-to-globule transition is observed for PNIPAM above a lower critical solution temperature (LCST) of 305 K whereas the same is absent in PAAM. Simulations in both the cases are performed above and below the LCST of PNIPAM, namely at 278 K and 310 K, to evaluate the effect of temperature on the polymer conformations. The vibrational spectra of bonds involving atoms from the polymer backbone and the various side-groups (amide I, amide II, and isopropyl group of PNIPAM and amide I and amide II group of PAAM) of the polymers were analyzed to study the conformational changes in the polymer. The differences in the vibrational spectra are used to understand the dynamics of conformational transitions in the two polymers and identify the changes in the relative interactions between various atoms in the backbone and in the side groups of the polymer with water at two different temperatures, namely at 278 K and 310 K. The systematic trends in the observed peak intensities and frequency shifts at the low, medium, and high frequency end of the spectrum for the various atoms in the two polymers are rationalized on the basis of bond-lengths, local coordination, strength of hydrogen bonding, and neighboring solvation environment. The analysis of the vibrational spectra for amide I and amide II regions of PNIPAM suggests a coil-to-globule transition in going from 278 K to 310 K. The differences are evaluated in terms of the strength, stability, and structure of the hydrogen-bond network between polymer and polymer and between polymer and water. Comparison of the vibrational spectra of isopropyl groups in PNIPAM at 278 K and 310 K suggests dehydration of the isopropyl moieties at 310 K. In the case of PNIPAM, we observe that polymer-water interactions are dominant below the LCST whereas polymer–polymer interactions dominate above the LCST. On the other hand, the vibrational spectra of amide I and amide II group of PAAM, at 278 K and 310 K, do not show any significant difference in terms of the interactions between polymer and polymer and interactions between polymer and water. Analysis of the peak intensities, of the amide II stretching band, observed in the frequency range 3500–3700 cm^?1 suggests that the fraction of bonded and non-bonded hydrogen atoms are similar at both 278 K and 310 K. This indicates that the interactions between polymer and polymer and between polymer and water are similar at both the temperatures. The interactions between PAAM and its surrounding environment are found to be unaffected as the temperature is raised from 278 K to 310 K. Comparisons with experimental studies are made where possible. Our study provides useful insights into the nature of various inter-molecular interactions and their role in influencing the atomic scale conformational dynamics in oligomers.     

Characterization of poly(N-vinyl-2-pyrrolidone)s with broad size distributions

We report on the characterization of the solution structure of poly(N-vinyl-2-pyrrolidone)s (PVP) by small-angle X-ray scattering (SAXS) and by online coupling of asymmetrical flow field-flow fractionation (A4F), SAXS and dynamic light scattering (DLS). The commercial products PVP K30 and PVP K90 with nominal molar masses of 40 × 10³ and 360 × 10³ g mol⁻¹, respectively, were investigated separately and as binary mixture. Detailed information for all polymer fractions is available on the polymer contour lengths and the diffusion coefficients. Key areas of applications for the A4F-SAXS-DLS coupling are seen in comparison to static light scattering for polymers with radii of gyration smaller than 10 nm, for which only SAXS produces precise analytical results on the size of the polymers in solution.     

Influence of chromophoric electron-withdrawing groups on photoinduced deformation of azo polymer colloids

This study investigated the influence of chromophoric electron-withdrawing groups on photoinduced deformation behavior of colloidal spheres of three azo polymers. The colloidal spheres were prepared by using the epoxy-based azo polymers (BP-AZ-CA, BP-AZ-CN, and BP-AZ-NT) through gradual hydrophobic aggregation of the polymers in THF-H₂O media. The colloidal spheres were controlled to have similar average sizes by adjusting both the polymer concentrations in the initial THF solutions and water-adding rates in the preparation processes. The colloids were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The colloid deformation was investigated by irradiating the colloidal spheres in solid state with a linearly polarized Ar⁺ laser beam (488 nm, 130 mW/cm²). For comparison, the colloids were also studied by irradiation with a polarized diode solid state laser beam (532 nm, 130 mW/cm²). Upon the light irradiation, all the colloidal spheres were elongated along the polarization direction of the laser beams. The electron-withdrawing groups showed significant influence on the colloid deformation behavior related with the response to the light irradiation. The colloid deformation was more efficiently induced by irradiation with the laser beams having the intermediate wavelengths between the λ_max and the absorption band tails of the azo chromophores. When the hydrophilic carboxylic group was used as the electron-withdrawing groups, more significant deformation was induced under the same light irradiation condition, which could be attributed to the higher hydrophilicity of the polymer. Above observations can lead to a better understanding of the photoinduced deformation mechanism of azo polymer colloids.     

Cost effective cation exchange membranes: A review

This paper will look at developments of new polymer electrolyte membranes to replace high cost ion exchange membranes such as Nafion^®, Flemion^® and Aciplex^®. These perfluorinated polymer electrolytes are currently the most commercially utilized electrolyte membranes for polymer electrolyte fuel cells, with high chemical stability, proton conductivity and strong mechanical properties. While perfluorinated polymer electrolytes have satisfactory properties for fuel cell applications, they limit commercial use due to significant high costs as well as reduced performance at high temperatures and low humidity. A promising alternative to obtain high performance proton-conducting polymer electrolyte membranes is through the use of hydrocarbon polymers. The need for inexpensive and efficient materials with high thermal and chemical stability, high ionic conductivity, miscibility with other polymers, and good mechanical strength is reviewed in this paper. Though it is difficult to evaluate the true cost of a product based on preliminary research, this paper will examine several of the more promising materials available as low cost alternatives to ion exchange membranes. These alternative membranes represent a new generation of cost effective electrolytes that can be used in various ion exchange systems. This review will cover recent and significant patents regarding low cost polymer electrolytes suitable for ion exchange membrane applications. Promising candidates for commercial applications will be discussed and the future prospects of cost effective membranes will be presented.