Proton‐conducting blend membranes of crosslinked poly(vinyl alcohol)–sulfosuccinic acid ester and poly(1‐vinyl‐1,2,4‐triazole) for high temperature fuel cells

New type of composite membranes were synthesized by crosslinking of poly(vinyl alcohol) (PVA) with sulfosuccinic acid (SSA) and intercalating poly(1‐vinyl‐1,2,4‐triazole) (PVTri) into the resulting matrix. The complexed structure of the membranes was confirmed by Fourier transform infrared (FTIR) spectroscopy. The resulting hybrid membranes were transparent, flexible, and showed good thermal stability up to ～200°C. The proton conductivities of the membranes were investigated as a function of PVTri and SSA and operating temperature. The water/methanol uptake was measured and the results showed that solvent absorption of the materials increased with increasing PVTri content in the matrix. The proton conductivity of the membranes continuously increased with increasing SO₃H content, PVTri content, and the temperature. In the anhydrous state, the maximum proton conductivity is 7.7 × 10^?5 S/cm for PVA–SSA–PVTri‐1 and for PVA–SSA–PVTri‐3 is 1.6 × 10^?5 S/cm at 150°C. After humidification (RH = 100%), PVA–SSA–PVTri‐4 showed a maximum proton conductivity of 0.0028 S/cm at 60°C. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Entrapment of urease in poly(1‐vinyl imidazole)/poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) network

In this article, urease was immobilized in a conducting network via complexation of poly(1‐vinyl imidazole) (PVI) with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS). The preparation method for the polymer network was adjusted by using Fourier transform infrared (FTIR) spectroscopy. A scanning electron microscope (SEM) study revealed that enzyme immobilization had a strong effect on film morphology. The proton conductivity of the PVI/PAMPS network was measured via impedance spectroscopy, under humidified conditions. The basic characteristics (Michealis‐Menten constants, pH_opt, pH_stability, T_opt, T_stability, reusability, and storage stability) of the immobilized urease were determined. The obtained results showed that the PAA/PVI polymer network was suitable for enzyme immobilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

New highly proton-conducting membrane poly(vinylpyrrolidone)(PVP) modified poly(vinyl alcohol)/2-acrylamido-2-methyl-1-propanesulfonic acid (PVA-PAMPS) for low temperature direct methanol fuel cells (DMFCs)

A new type of chemically cross-linked polymer blend membranes consisting of poly(vinyl alcohol) (PVA), 2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) and poly(vinylpyrrolidone) (PVP) have been prepared and evaluated as proton conducting polymer electrolytes. The proton conductivity (σ) of the membranes was investigated as a function of cross-linking time, blending composition, water content and ion exchange capacity (IEC). Membranes were also characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), and the differential scanning calorimetry (DSC). Membrane swelling decreased with cross-linking time, accompanied by an improvement in mechanical properties and a small decrease in proton conductivity due to the reduced water absorption. The membranes attained 0.088 S cm⁻¹ of the proton conductivity and 1.63 mequiv g⁻¹ of IEC at 25±2 °C for a polymer composition PVA-PAMPS-PVP being 1:1:0.5 in mass, and a methanol permeability of 6.1×10⁻⁷ cm² s⁻¹, which showed a comparable proton conductivity to Nafion 117, but only one third of Nafion 117 methanol permeability under the same measuring conditions. The membranes displayed a relatively high oxidative durability without weight loss of the membranes (e.g. 100 h in 3% H₂O₂ solution and 20 h in 10% H₂O₂ solution at 60 °C). PVP, as a modifier, was found to play a crucial role in improving the above membrane performances.     

Intrinsically proton-conducting poly(1-vinyl-1,2,4-triazole)/triflic acid blends

In the present work, proton conductivity in a polymer blend comprising proton solvating heterocycles was examined. Poly(1-vinyl-1,2,4-triazole), PVTri was produced by free radical polymerization of 1-vinyl-1,2,4-triazole and then proton-conducting polymer electrolytes were obtained by blending of PVTri with trifluoromethanesulfonic acid, triflic acid (TA). To promote the intrinsic proton conductivity the percent blending ratio was changed from 25% to 150% with respect to polymer repeat unit. The protonation of aromatic heterocyclic rings was proved with Fourier-transform infrared spectroscopy (FT-IR). Thermogravimetry (TG) analysis showed that the samples are thermally stable up to approximately 300 °C. Differential scanning calorimetry (DSC) results illustrated that the samples are homogeneous and their glass transition temperatures are located within 130-160 °C. The surface morphology of the materials were characterized by scanning electron microscopy (SEM). The proton conductivity of the blends increased with triflic acid concentration and the temperature. In the anhydrous state, the proton conductivity of PVTriTA100 is 2.2 × 10⁻⁴ S/cm at 150 °C and that of PVTriTA150 is approximately 0.012 S/cm at 80 °C which is similar to that of hydrated Nafion^®.     

Synthesis and proton conductivity of poly(styrene sulfonic acid)/heterocycle‐based membranes

BACKGROUND: High proton conduction through anhydrous polymer electrolyte membranes is crucial for the application to chemical energy conversion devices such as fuel cells. In this context, novel proton conductors were produced by doping poly(styrene sulfonic acid) (PSSA) with 1H‐1,2,4‐triazole (Tri) and 1.12‐diimidazol‐2‐yl‐2,5,8,11‐tetraoxadodecane (imi3), and their physicochemical properties were investigated. RESULTS: Different polymer electrolyte membranes were produced by doping of PSSA with Tri and imi3. PSSATri_x and PSSAimi3_x electrolytes were obtained where x is the doping ratio describing moles of Tri or imi3 per mole of ? SO₃H unit. The membranes demonstrated adequate thermal stability at least up to 200 °C and the dopants acted as plasticizers shifting the T_g values to lower temperatures. PSSATri₁ has a maximum proton conductivity of 0.016 S cm^?1 at 150 °C and the proton conductivity of PSSAimi3_0.5 is approximately 10^?4 S cm^?1 at room temperature. CONCLUSIONS: Transparent, homogeneous and freestanding films of PSSATri_x and PSSAimi3_x were produced. It was demonstrated that both Tri and imi3 are efficient proton solvents in PSSA host matrix, and they yielded promising defect‐type conductivities compared to benzimidazole. Tri‐doped membranes clearly showed better conductivity performance at higher temperatures (T > 100 °C). Both PSSATri_x and PSSAimi3_x polymer electrolytes can be suggested for fuel cell applications. Copyright © 2007 Society of Chemical Industry     

Proton conducting polymer blends from poly(2,5‐benzimidazole) and poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)

Proton conducting polymer electrolyte membranes were produced by blending of poly(2,5‐benzimidazole) (ABPBI) and poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS) at several stoichiometric ratios with respect to polymer repeating units. The membranes were characterized by using Fourier transform infrared spectroscopy for interpolymer interactions and scanning electron microscope for surface morphology. Thermal stability of the materials was investigated by thermogravimetric analysis. Glass transition temperatures of the samples were measured via differential scanning calorimetry. The spectroscopic measurements and water uptake studies indicate a complexation between ABPBI and PAMPS that inhibited polymer exclusion up on swelling in excess water. Proton conductivities of the anhydrous and humidified samples were measured using impedance spectroscopy. The proton conductivity of the humidified ABPBI:PAMPS (1 : 2) blend showed a proton conductivity of 0.1 S/cm, which is very close to Nafion 117, at 20°C at 50% relative humidity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Polymer Electrolytes Based on Polymeric Ionic Liquid Poly(methyl 2-(3-vinylimidazolidin-1-yl)acetate bis(trifluoromethane sulfonyl)imide)

A new kind of ionic liquid monomer methyl 2-(3-vinylimidazolidin-1-yl)acetate bromide (MVIm-Br) and polymeric ionic liquid (PIL), poly(methyl 2-(3-vinylimidazolidin-1-yl)acetate bis(trifluoromethanesulfonyl)imide) (PMVIm-TFSI), were synthesized and characterized. Different compositions of polymer electrolytes were prepared by blending PMVIm-TFSI and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) with poly(methylmethacrylate-co-vinyl acetate) (P(MMA-VAc)). The thermal stability and ionic conductivity improved significantly when PMVIm-TFSI was added into P(MMA-VAc)/LiTFSI polymer. For the polymer electrolytes obtained, the highest ionic conductivity at 30 °C is 4.71 × 10⁻⁴ S cm⁻¹ and the corresponding decomposition temperature is ca. 308 °C. Moreover, P(MMA-VAc)/PMVIm-TFSI/LiTFSI electrolyte membrane (transmittance ≥90%) can be used as the ion-conductive layer material for electrochromic devices, which reveal excellent electrochromic performance.     

Synthesis and NMR studies of the polymer membranes based on poly(4-vinylbenzylboronic acid) and phosphoric acid

Proton conduction in novel anhydrous membranes based on host polymer, poly(4-vinylbenzylboronic acid), (P4VBBA) and phosphoric acid, (H₃PO₄) as proton solvent was studied. The materials were prepared by the insertion of the proton solvent into P4VBBA at different stoichiometric ratios to get P4VBBA·xH₃PO₄ composite electrolytes. Homopolymer and the composite materials were characterized by FT-IR, ¹¹B MAS NMR and ³¹P MAS NMR. ¹¹B MAS NMR results suggested that acid doping favors or leads to a four-coordinated boron arrangement. ³¹P MAS NMR results illustrated the immobilization of phosphoric acid to the polymer through condensation with boron functional groups (B-O-P and/or B-O-P-O-B). Thermogravimetric analysis (TGA) showed that the condensation of composite materials starts approximately at 140 °C. An exponential weight loss above this temperature was attributed to intermolecular condensation of acidic units forming cross-linked polymer. The insertion of phosphoric acid into the matrix softened the materials shifting T_g to lower temperatures. The temperature dependence of the proton conductivity was modeled with Arrhenius relation. P4VBBA·2H₃PO₄ has a maximum proton conductivity of 0.0013 S/cm at RT and 0.005 S/cm at 80 °C.     

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     

Preparation of poly(2-pyridone-3,5-diyl)s with –(CH2)4–SO3M (M = H or Na) side chains

Poly(2-pyridone-3,5-diyl)s with –(CH₂)₄–SO₃M (M = H or Na) side chains have been prepared by nickel-complex promoted dehalogenative polycondensation. A composite film of the polymer with –(CH₂)₄–SO₃H side chains and poly(vinyl alcohol) showed a proton conductivity of 1.5 × 10^?1 S cm^?1 at 80 °C and 95% humidity. A copolymer with pyridine showed a high stability against oxidation by a Fenton reagent.     

New Antiferroelectric Solid Solution of Pb(Mg1/2W1/2)O3–Pb(Zn1/2W1/2)O3 as Dielectric Ceramics

A new solid solution of (1?x)Pb(Mg_1/2W_1/2)O₃–xPb(Zn_1/2W_1/2)O₃ has been prepared in the form of ceramics by solid‐state reaction with composition x up to 30%. It is found that with the substitution of Zn²⁺ for Mg²⁺ on the B site of the of complex perovskite structure the antiferroelectric (AFE) Curie temperature T_C of PMW increases from 40°C (x = 0) to 67°C (x = 30%), indicating an enhancement of antiferroelectric order, whereas, at the same time, the phase transition becomes more diffuse due to a higher degree of chemical inhomogeneity. X‐ray diffraction analysis indicates that the crystal structure adopts an orthorhombic space group (Pmcn) with a decrease in lattice parameter a, but an increase in b and c as the Zn²⁺ concentration increases. The low dielectric constant (~ 10²), low dielectric loss (tanδ ≈ 10^?3), linear‐field‐induced polarization, and significantly high breakdown field (~ 125 kV/cm) at room temperature make this family of dielectric materials a promising candidate for ceramic insulators.     

Poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium): Synthesis,characterization, and its potential application for the removal of metal ions from aqueous solution

In the current study, poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium), poly(VP‐co‐AMPS), was prepared and used for the removal of Cu²⁺, Cd²⁺, and Ni²⁺ ions via a polymer‐enhanced ultrafiltration (PEUF) technique. The copolymer was synthesized by radical polymerization in an aqueous medium with a comonomer feed composition of 50:50 mol %. The molecular structure of the copolymer was elucidated by ATR‐FTIR and ¹H NMR spectroscopy, and the average molecular weight was obtained by GPC. The copolymer composition was determined to be 0.42 for VP and 0.58 for AMPS by ¹H NMR spectroscopy. The copolymer and homopolymers exhibited different retention properties for the metal ions. PAMPS exhibited a high retention capacity for all of the metal ions at both pH values studied. PVP exhibited selectivity for nickel ions. Poly(VP‐co‐AMPS) exhibited a lower retention capacity compared to PAMPS. However, for poly(VP‐co‐AMPS), selectivity for nickel ions was observed, and the retention of copper and cadmium ions increased compared to PVP. The homopolymer mixture containing PAMPS and PVP was inefficient for the retention of the studied metal ions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41272.     

Synthesis,characterization, and ion exchange voltammetry study on 2‐acrylamido‐2‐methylpropane sulphonic acid and N‐(hydroxymethyl) acrylamide‐based copolymer

A random copolymer of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) and N‐hydroxymethyl acrylamide (NHMA) was prepared by solution polymerization using ceric ammonium nitrate as an initiator. A grade of poly(AMPS)‐co‐poly(NHMA) (PAMPS‐co‐PNHMA) random copolymer was synthesized with AMPS and NHMA. The homopolymerization of AMPS and NHMA was also carried out by the same way as that of random copolymer. PAMPS‐co‐PNHMA and homopolymers of AMPS and NHMA were characterized by FTIR, rheology, FT‐NMR, scanning electron microscope, thermal analysis, and X‐ray diffaractometry. Cyclic voltammetry is used to explain the ion exchange properties of PAMPS‐co‐PNHMA and its possible application in the trace analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Structural,thermal and dielectric properties of 2D layered Ti3C2Tx (MXene) filled poly (ethylene-co-methyl acrylate) (EMA) nanocomposites

Light-weight and flexible 2D MXene-based polymer materials with low dielectric loss and high dielectric constant have drawn great attention in the power systems and modern electronic field. A series of Ti₃C₂T_x/EMA composites were fabricated via simple solution casting followed by a compression molding method with various mass concentrations of Ti₃C₂T_x (0, 1, 3, 5, 8, 10, 12, and 15 wt%). Morphological and micro structural properties of the prepared composites were studied via X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM), where the distribution of Ti₃C₂T_x in the Ti₃C₂T_x/EMA composites was confirmed. Thermal behaviors were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) investigations. The DSC analysis reveals that the % of crystallinity decreases from 11.06 with 1 wt% to 5.68 with 15 wt%, where Ti₃C₂T_x acts as an efficient nucleating agent. TGA data confirm the enhancement of the thermal stability of the composites upon increasing in Ti₃C₂T_x loading. The room temperature electrical and dielectric behavior of the studied composites were examined in the frequency range of 100 Hz–5 MHz. In this work, the 10 wt% of Ti₃C₂T_x loaded poly (ethylene-co-methyl acrylate) composite (EMA) showed higher dielectric permittivity (ε′ = 124.22) with lower dissipation loss (tan δ = 0.051) at 100 Hz among all weight percentages. The behavior of charge carriers in the prepared composites was studied by utilizing the impedance spectroscopy technique. The electrical parameters were calculated from the fitted Nyquist plots with a corresponding circuit model. I–V curves confirmed the conduction mechanisms of the composites. This beneficial enhancement in electrical properties recommends the composite can be utilized in flexible electronic storage devices.     

Proton conducting PAMPS networks: From flexible to rigid materials

To elaborate tailor‐made proton conducting materials showing an interesting range of flexibility, a series of conetworks combining poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS) and poly(ethylene oxide) dimethacrylate (PEGDM) with various chain lengths was synthesized. The homogeneity of these conetworks was checked by differential scanning calorimetry and dynamic mechanical thermal analysis. The swelling behavior of these materials is strongly influenced by the amount of sulfonic acid groups and the endothermal peak temperature, characteristic of the presence of bound water in the conetwork, increases from 65 to 120°C when AMPS amount increases from 10 to 75 wt %. In addition, the proton conductivity of these materials varies from 10^?3 to 10^?1 S cm^?1, depending on the AMPS amount. The storage moduli were found to be affected by both the AMPS content in the conetwork and its crosslinking density. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and characterization of novel hybrid thermoplastic poly(ether urethane)/poly(vinylidene fluoride) elastomers,and their application as solid polymer electrolytes

A comb‐like polyether, poly(3‐2‐[2‐(2‐methoxyethoxy)ethoxy]ethoxymethyl‐3′‐methyloxetane) (PMEOX), was reacted with hexamethylene diisocyanate and extended with butanediol in a one‐pot procedure to give novel thermoplastic elastomeric poly(ether urethane)s (TPEUs). The corresponding hybrid solid polymer electrolytes were fabricated through doping a mixture of TPEU and poly(vinylidene fluoride) with three kinds of lithium salts, LiClO₄, LiBF₄ and lithium trifluoromethanesulfonimide (LiTFSI), and were characterized using differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. The ionic conductivity of the resulting polymer electrolytes was then assessed by means of AC impedance measurements, which reached 2.1 × 10^?4 S cm^?1 at 30 °C and 1.7 × 10^?3 S cm^?1 at 80 °C when LiTFSI was added at a ratio of O:Li = 20. These values can be further increased to 3.5 × 10^?4 S cm^?1 at 30 °C and 2.2 × 10^?3 S cm^?1 at 80 °C by introducing nanosized SiO₂ particles into the polymer electrolytes. Copyright © 2006 Society of Chemical Industry     

An investigation of lithium ion conductivity of copolymers based on P(AMPS-co-PEGMA)

In this work, a series of novel lithium ion-conducting copolymer electrolytes based on 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and poly(ethyleneglycol) methacrylate (PEGMA) were produced and characterized. The copolymers were synthesized by free-radical polymerization of the corresponding monomers with three different feed ratios to form P(AMPS-co-PEGMA)-based electrolytes. After the polymerization, AMPS units of the copolymers were lithiated via ion exchange. The characterization of the electrolytes was done by ¹H-NMR, FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction, scanning electron microscopy (SEM), and impedance analyzer. The copolymers were thermal stable approximately to 200 °C. Single T_g transitions in DSC curves verified the homogeneity as well as amorphous characteristics. SEM further confirmed the homogeneity of the electrolytes. The lithium ion conductivity of these new polymer electrolytes was studied by impedance dielectric impedance analyzer and the effect of PEGMA contents onto the ionic conductivity of these copolymer electrolytes were investigated. It was observed that the temperature dependence of ionic conductivity was interpreted over Vogel Tammann Fulcher model. The Li ion conductivity increased by PEGMA content and S3 has maximum conductivity of 3 × 10⁻³ mS cm⁻¹ at 100 °C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47798.     

(Sr1-xCax)2TiO4 microwave dielectric ceramics with R-P structure (x = 0~0.15)

(Sr_1-xCa_x)₂TiO₄ ceramics (0 ≤ x ≤ 0.15) were synthesized by a standard solid state reaction route. Tetragonal Ruddlesden-Popper (R-P) solid solutions (Sr_1-xCa_x)₂TiO₄ with space group I4/mmm were obtained in the composition range of x = 0~0.15, while Sr₃Ti₂O₇ has been observed as secondary phase in x ≤ 0.10. In the present ceramics, both the dielectric constant ɛ_r and temperature coefficient of resonant frequency τ_f decreased at first and turned to increase again with increasing x, while the quality factor Qf decreased slightly at first and turned to decrease sharply after x = 0.1. The improved microwave dielectric properties with the best combination were obtained in (Sr_1-xCa_x)₂TiO₄ ceramics at x = 0.075: ɛ_r = 39.3, Qf = 93 550 GHz, τ_f = 119 ppm/°C The obvious improvement was achieved in temperature coefficient of resonant frequency (from 140 to 119 ppm/°C) with Ca²⁺-substitution for Sr²⁺ in Sr₂TiO₄ ceramics due to the increased B-site bond valance.     

Synthesis and properties of regio-regular poly(2-furyloxirane) using tri-isobutyl aluminium as catalyst

2-Furyloxirane(FO) with purity of over 99% was prepared in 80% yield by epoxidation of furfural with trimethylsulfonium chloride and potassium hydroxide in acetonitrile/water solution. Polymerization of FO was realized using tri-isobutyl aluminum (Al(i-Bu)₃) as catalyst, when Al(i-Bu)₃ concentration was 0.009 mol/L, poly(2-furyloxirane)(PFO) with M _n of 3.4 kg/mol and a polydispersity index of 1.5 was obtained in yield of 88% after polymerization at 25 °C for 48 h. The corresponding PFO showed glass transition temperature (T _g ) of Ca. 1 °C and 5 wt% thermal decomposition temperature(T _d ) of 260 °C. The obtained PFO was almost 100% head-to-tail structure, and it was a good plasticizer and thermal stabilizer for poly(propylene carbonate)(PPC), an alternate copolymer of propylene oxide and carbon dioxide. For PFO/PPC polyblend with PFO loading of 2 wt%, its T _d increased by 50 °C from 214 °C of pure PPC to 264 °C, while its elongation at break increased from 13% of pure PPC to 29%.     

Geometrical structures in solution and solid phase of poly(propargyl ester)s prepared by using a [Rh(norbornadiene)Cl]2-cocatalyst

Propargyl esters, HCCCH₂OCOC_nH_2n+1 (1: n = 3, 2: n = 5, 3: n = 9, and 4: n = 13), were polymerized using a [Rh(nbd)Cl]₂ catalyst and cocatalyst in an appropriate solvent at 0 °C and 40 °C. Number average molecular weights, M_n of the resulting polymers, poly(1)–poly(4), were 8000–54,000, and its dispersities (M_w/M_n)s and the yields were estimated to be 1.6–3.6 and ca. ～99%, respectively. These polymers were soluble in CHCl₃, CH₂Cl₂, and THF, and insoluble in CH₃OH and DMF. The amines, e.g., 2,6-dimethylpyridine and triethylamine worked well as the cocatalysts for the polymerization to give the yields, 93% and 88%, respectively. Further N,N-diethylaniline gave the maximum in cis%, 74%, although pyridine, aniline, pyrrole or imidazole did not work effectively. Remarkable line broadening phenomenon, LBP observed in the ¹H NMR spectra of poly(1) and poly(2) prepared at 0 °C or 40 °C, and poly(3) prepared at 40 °C was correlated with the polymerization temperature and the radical concentration generated in the polymer. The LBP was interpreted by the dipole–dipole interaction between the protons in the polymer and unpaired electrons due to carbon radicals generated by the rotational scission of the cis CC bonds during the polymerization. Their UV–vis spectral shape of poly(1)–poly(4) depended on the polymerization temperature and/or the alkyl chain length in the polymer. The XRD powder patterns of poly(3) prepared at 0 °C, and poly(4)s prepared at 0 °C and 40 °C showed layer crystal structures with a slightly bent herringbone confirmed by molecular mechanics calculation. The λ_max values of poly(4) prepared at 40 °C in methanol showed 317 nm and 340 nm in the solution and on the alumina, respectively.