Studies on stable aqueous poly(o-toluidine) prepared with the use of a water soluble support polymer,polyacrylamide

Polymerization of o-methylaniline or o-toluidine (OT) was studied in aqueous acidic (HCl) medium with or without the use of the support of a water soluble polymer, polyacrylamide (PAAm). Poly(o- toluidine) (POT) produced with PAAm support was in the form of aqueous solution or dispersion that showed high stability and good processibility. High degree of dispersion or near solubility and storage stability of POT thus prepared are explained on the basis of establishment of hydrogen bonding between segments of POT being formed and the PAAm present in the medium thus resulting in a template effect. Studies by UV-visible spectroscopy and FTIR spectroscopy lend support to this view. POT-PAAm composites commonly show higher thermal stability than POT and the composites show DC-electrical conductivities in the range of 10⁻⁹–10⁻¹ S · cm⁻¹ depending on the POT content. Morphological analysis of the optically clear aqueous POT-PAAm solution by transmission electron microscopy (TEM) shows the presence of large clusters of PAAm-supported near-spherical POT nanoparticles in the aqueous PAAm solution. Scanning electron microscopic (SEM) analysis of isolated POT-PAAm composites shows a cocontinuous phase morphology without any trend of gross phase separation. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3243–3256, 1999     

New aromatic benzazole polymers II: Synthesis and conductivity of benzobisthiazole-co-polymers incorporated with 4-N,N-dimethylaminotriphenylamine groups

New aromatic benzobisthiazole copolymers containing 10–70 mol % of 4-N,N-dimethylamino-triphenylamine functionality were prepared from the respective dinitrile or dicarboxylic acid monomers, terephthalic acid, and 2,5-diamino-1,4-benzene-dithiol dihydrochloride in polyphosphoric acid. At the first approximation, the copolymers containing 10 mol % or less of the triarylamino moieties in the polymer chains still preserve the capability to form anisotropic (nematic) solutions at 10 wt % polymer concentration. This is an important requirement for processing the copolymers into fibers and films with good to excellent mechanical properties. Films with good mechanical integrity were cast from the dilute methanesulfonic acid solutions of the copolymers under reduced pressure. They showed electrical conductivity values of the order of 10⁻¹¹–10⁻¹⁰ S/cm in pristine state, with four to seven orders of magnitude increase upon exposure to mild oxidizing agents such as iodine vapor. On the contrary, the parent polymer, poly(p-phenylene benzobisthiazole) is an insulator with conductivity of less than 10⁻¹² S/cm, and its conductivity does not improve at all with exposure to iodine vapor. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 713–724, 1998     

New aromatic benzazole polymers. I. Benzobisthiazole and benzobisoxazole polymers with main-chain triarylamino units

Thermally stable, nonrigid-rod poly(benzobisthiazoles), (R)TPA-PBZT , where R = H, Me, NMe₂, and OH, and poly(benzobisoxazoles), (R)TPA-PBO , where R = Me, NMe₂ containing electron-rich triarylamine groups with various para-substituents (Rs) on the pendent phenyl ring, were synthesized from either 2,5-diamino-1,4-benzenedithiol dihydrochloride or 2,4-diamino-1,5-benzenediol dihydrochloride and the respective triarylamine-based dinitrile or diacid monomer in polyphosphoric acid. Whereas (R)TPA-PBZT polymers were obtained in moderate molecular weights, analogous (R)TPA-PBO polymers were only prepared in low molecular weights. No lyotropic behaviors, characteristic of the unmodified rigid-rod benzazole polymers, as evidenced by the absence of either stir opalescence or birefringence under crosspolarizers, were observed for these homopolymers at about 10 wt % polymer concentration. Among these polymers, only (Me)TPA-PBZT and (NMe₂)TPA-PBZT formed cast films with good mechanical integrity. In their pristine state, their film conductivity values were in the range of 10⁻¹⁰–10⁻⁹ S/cm at room temperature. Upon exposure to iodine vapor, their conductivities were increased to the maximal values of 5.0 × 10⁻⁵ S/cm ( (Me)TPA-PBZT ) and 4.1 × 10⁻⁴ S/cm ( (NMe₂)TPA-PBZT ). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1909–1924, 1997     

Enzymatic synthesis and characterization of a water-soluble, conducting poly(o-toluidine)

An enzymatic method for the synthesis of a water-soluble, conducting poly(o-toluidine) (POT) in the presence of sulfonated polystyrene (SPS) is presented. The enzyme horseradish peroxidase was used to polymerize o-toluidine to form a water-soluble, conducting POT/SPS complex, which exhibits moderate electrical conductivity. The synthesis is simple and the conditions are mild. The polymerization may be carried out at room temperature in pH 4.3 buffered aqueous solution with stoichiometric amount of monomer, SPS, hydrogen peroxide and catalytic amount of enzyme. The UV-Vis absorption spectra of the products display a distinct absorption peak at 740 nm at pH 4.3 that indicates the formation of the conducting, emeraldine salt form of POT. The structure and electrochemical behavior of the polymer was investigated with FT-IR and cyclic voltammetry method.     

Synthesis,characterization, and thermal and dielectric properties of three different methacrylate polymers with zwitterionic pendant groups

The synthesis, characterization, thermal, and dielectric properties of three different zwitterionic methacrylates of the sulfobetaine type are presented. Diethylamine-ethyl-, 2-(diethylaminoethoxy)-ethyl-, and 2-(2-diethylaminoethoxy) ethoxy-ethyl-methacrylates were made to react with butanosultone to prepare monomers with variable flexibility. The flexibility of the lateral chain of the polymethacrylates decreased the glass transition temperature (T_g down to 300 K) of the polymers. A linear relationship between T_g and the number of carbon atoms was shown for these materials. X-ray diffraction and DSC experiments showed the formation of new ordered phases in these polymers, which inhibited their dipole conductivity. On heating, these phases were destroyed and values of conductivity of 10⁻⁷–10⁻³ S cm⁻¹ were obtained in the studied range of temperature. Variation of conductivity with temperature was established according to the Arrhenius equation. Dielectric properties exhibited a small deviation of the Debye type behavior, and β parameters of the Cole–Cole equations were calculated for the synthesized polymers. © 1997 John Wiley & Sons, Inc.     

Adsorption of anionic methyl orange dye by polyaniline,poly(o-methylaniline) and poly(o-methoxyaniline)

This study reports the effect of substituents in the ortho position of polyaniline on the adsorption capacity to remove the anionic dye methyl orange (MO) from an aqueous solution. The aim of this study is the synthesis of polyaniline (PANI) and its derivatives, poly-o-methylaniline (poly-o-toluidine, POT) and poly-o-methoxyaniline (poly-o-anisidine, POA) for the adsorption removal of MO dye. All polymers were obtained by oxidative polymerization of the corresponding monomers and characterized by scanning electron microscopy (SEM) and infrared spectroscopy (IR). The average particle size of the polymer was about 200 nm. The effect of various parameters such as pH, temperature, adsorption time and initial concentration was analyzed. It was found that the adsorption capacity for dye removal increases from 50.68 to 222.56 mg g⁻¹ for PANI, from 16.89 to 66.57 mg g⁻¹ for POT, and from 97.26 to 532.54 mg g⁻¹ for POA with an increase in the initial dye concentration from 5 up to 50 mg L⁻¹. For all polymers, the equilibrium state of MO adsorption was reached in 50 min. The results showed that MO adsorption on PANI, POT, and POA is well described by a pseudo second order kinetic model. Isothermal studies have shown that adsorption is in good agreement with the Langmuir isotherm model, as evidenced by higher values of correlation coefficients. Based on the data of thermodynamic studies, it was concluded that MO adsorption on PANI, POT, and POA is spontaneous and endothermic.     

Miscibility and Thermal Behaviour of Poly(styrene-co-itaconic acid)/Poly(butyl methacrylate-co-4-vinylpyridine) Mixtures. Accessibility and Self-Association Effects

Summary: The miscibility and thermal behaviour of binary mixtures of poly(styrene-co-itaconic acid) containing 11 or 27 mol % of itaconic acid (PSIA-11 or PSIA27) with poly(butyl methacrylate) (PBMA)or poly(butyl methacrylate-co-4-vinylpyridine) containing 10 or 26 mol% of 4-vinylpyridine (PBM4VP-10, PBM4V-P26) were investigated by differential scanning calorimetry, scanning electron microscopy, FTIR spectroscopy and thermogravimetry. The results showed that 11 mol % of itaconic acid and 10 mol % of 4-vinylpyridine respectively introduced within the polystyrene and poly(butyl methacrylate) matrices induced the miscibility of this pair of polymers due to specific interactions of hydrogen bonding type with partial pyridine protonation that occurred between the two copolymers as evidenced by FTIR from the appearance of two new bands at 1607 cm⁻¹ and 1640 cm⁻¹. Increasing itaconic acid content from 11 to 27 mol % led to a decrease of the intensity of the specific interactions within PSIA-27/PBM4VP blends and is attributed to both accessibility and self association effects as evidenced by DSC from the change of the shape of the Tg- composition curves and by FTIR spectroscopy. As shown from the thermogravimetric study, the presence of these specific interactions delayed the anhydride formation and improved the thermal stability of the blends.     

The electromagnetic properties of blends of poly(p‐phenylene‐vinylene) derivatives

We report the studies on the frequency dependence of the complex permittivity, and on the electromagnetic interference (EMI) shielding of conductive blends. The blends were obtained from conjugated oligomers of (p‐phenylene‐1,3,5‐hexatrienylene) end‐capped by Schiff base units and dispersed in an insulating matrix of poly(vinyl chloride) (PVC) and doped with sulfuric acid, H₂SO₄. Permittivity measurements from 10 kHz to 10 GHz have pointed out that the electrical conductivity of composites were in a range 10⁻⁵–10⁺¹ S/cm. From these experimental data performed on 250–500 µm, the reflectivity coefficients [R(dB)] have been calculated for simulation of mm thick samples, they have values of −9 to −20 dB depending on the frequency and on the thickness of the composites. These permitivity data have also allowed us to develop modelization of the radioelectric properties of conductive blends, using McLachlan's General Effective Medium (GEM) Theory. The optimization of the GEM parameters suggests some informations about the shape of the particles as well as the micro/macrostructure of the composite materials. Copyright © 2000 John Wiley & Sons, Ltd.     

Comparative studies of solid‐state synthesized poly(o‐methoxyaniline) and poly (o‐toluidine)

Poly(o‐methoxyaniline) (POMA) and poly(o‐toluidine) (POT) salts doped with different acids (methanesulphonic acid (MeSA), trifluoroacetic acid (TFA), and hydrochloric acid (HCl)) were synthesized by using solid‐state polymerization method. The polymers were characterized by Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–Vis) spectrometry, X‐ray diffraction (XRD), cyclic voltammetry (CV), and conductivity measurements. Transmission electron microscopy (TEM) was done to study the morphologies of POMA and POT salts. The FTIR and UV‐Vis absorption spectra revealed that the reduced phase was predominant in POMA salts, and the pernigraniline phase was predominant in POT salts. It was found that POMA salts displayed higher doping level and conductivity. In contrast, POT salts were lower at doping levels and conductivity. In accordance with these results, the electrochemical activity was also found to be lower in POT salts. The XRD patterns showed that the POMA salts displayed higher crystallinity than POT salts. The results from TEM revealed that the morphologies of POMA salts were different from those of POT salts. Copyright © 2008 John Wiley & Sons, Ltd.     

Cross‐linked poly(aryl ether sulfone) membranes for direct methanol fuel cell applications

Partially sulfonated poly(aryl ether sulfone) (PESS) was synthesized and methacrylated via reaction with glycidyl methacrylate (PESSGMA) and cross‐linked via radical polymerization with styrene and vinyl‐phosphonic acid (VPA). The chemical structures of the synthesized pre‐polymers were characterized via FTIR and ¹H NMR spectroscopic methods and molecular weight was determined via GPC. Membranes of these polymers were prepared via solution casting method. The crosslinking of the PESS polymer reduced IEC, proton conductivity, swelling in water, and methanol permeability of the membranes while increasing the modulus and the glass transition temperature. However, the introduction of the VPA comonomer increased the proton conductivity while maintaining excellent resistance to methanol cross‐over, which was significantly higher as compared with both PESS and the commercial Nafion membranes. Membranes of PESSGMA copolymers incorporating VPA, exhibited proton conductivity values at 60 °C in the range of 16–32 mS cm⁻¹ and methanol permeability values in the range of 6.52 × 10⁻⁹ – 1.92 × 10⁻⁸ cm² s⁻¹. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 558–575     

Study on the preparation and the self‐assembly of poly(propyleneimine)–poly(styrene) nanoparticles

Using 2‐chloropropionamide derivative of poly(propyleneimine) dendrimer DAB‐dendr‐(NH₂)₃₂ (DAB‐32‐Cl) as the macroinitiator, atom transfer radical polymerization of styrene was successfully carried out in DMF medium. The monodisperse poly(propyleneimine)–polystyrene (dendrimer–PSt) particles with diameters smaller than 100 nm could be prepared. The morphology, size, and size distribution of the dendrimer–PSt particles were characterized by transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). The effects of reaction temperature, the ratio of St/macroinitiator, and reaction time on the size, and size distribution of the dendrimer–PSt nanoparticles were investigated. In a selective solvent (DMF/H₂O), polymers can self‐assemble into different aggregate configurations such as regular microsphere and wire‐like thread. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2658–2666, 2008     

Infrared spectra of soluble polytoluidines

IR spectra of soluble poly-o-toluidine (POT) and poly-m-toluidine (PMT) have been studied. Preliminary assignment of their IR spectra is given by comparing their spectra in HCl and I₂, doped states and in subsequently NH₃ dedoped state with that in intrinsic state.     

Synthesis and characterization of novel dendritic (arborescent,hyperbranched) polyisobutylene–polystyrene block copolymers

The synthesis of novel arborescent (arb; randomly branched, “tree‐like,” and often called “hyperbranched”) block copolymers comprised of rubbery polyisobutylene (PIB) and glassy polystyrene (PSt) blocks (arb‐PIB‐b‐PSt) is described. The syntheses were accomplished by the use of arb‐PIB macroinitiators (prepared by the use of 4‐(2‐methoxyisopropyl) styrene inimer) in conjunction with titanium tetrachloride (TiCl₄). The effect of reaction conditions on blocking of St from arb‐PIB was investigated. Purified block copolymers were characterized by ¹H NMR spectroscopy and Size Exclusion Chromatography (SEC). arb‐PIB‐b‐PSt with 11.7–33.8 wt % PSt and M_n = 468,800–652,900 g/mol displayed thermoplastic elastomeric properties with 3.6–8.7 MPa tensile strength and 950–1830% elongation. Samples with 26.8–33.8 wt % PSt were further characterized by Atomic Force Microscopy (AFM), which showed phase‐separated mixed spherical/cylindrical/lamellar PSt phases irregularly distributed within the continuous PIB phase. Dynamic Mechanical Thermal Analysis (DMTA) and solvent swelling of arb‐PIB‐b‐PSt revealed unique characteristics, in comparison with a semicommercial PSt‐b‐PIB‐b‐PSt block copolymer. The number of aromatic branching points of the arb‐PIB macroinitiator, determined by selective destruction of the linking sites, agreed well with that calculated from equilibrium swelling data of arb‐PIB‐b‐PSt. This method for the quantitative determination of branching sites might be generally applicable for arborescent polymers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1811–1826, 2005     

Studies on CSA-induced processability of conducting poly(o-toluidine) and its polyblend with ABS

Poly(o-toluidine) emeraldine base (EB) has been protonated with d,l -camphor sulfonic acid (HCSA). The CSA-doped poly(o-toluidine) (POT-CSA) is completely soluble in m-cresol, and the electrical conductivity is ∼ 28 S/cm. The incorporation of CSA has been proved by means of UV-Vis and IR spectroscopy. Thermogravimetric (TG)/mass (MS) analysis shows that POT-CSA is stable up to 180°C indicating the processability with other insulating polymers upto this temperature. TG curve of POT-CSA yields a four step decomposition pattern, and the degradation of the polymer backbone starts at 430°C. The thermal elimination of CSA occurs in the temperature range of 180 to 430°C. The viscometric and spectroscopic results suggest the change in molecular conformation from the compact coil to the expanded coil type which is enhanced by increasing the protonation level of EB by the addition of HCSA. The conductivity data were well equivalent to the viscometric data. Furthermore, POT-CSA-ABS (acrylonitrile/butadiene/styrene) blends were successfully fabricated with an extremely low percolation threshold of 2.66%. The scanning tunneling microscopic (STM) results reveal that the low percolation threshold reflects the formation of interconnecting path of conducting particles in ABS matrix. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2657–2665, 1999     

Single-ion and salt conductor polymer electrolytes based on poly(4-vinylpyridine) quaternized with poly(ethylene oxide) side chains

A new type of single-ion conductor with fixed cation was synthesized by spontaneous anionic polymerization of 4-vinylpyridine in the presence of short polyethylene oxide ( PEO ) chains as alkylating agents. These comblike polymers have low T_gs and are amorphous with the shorter PEO s. Their conductivities are unaffected by the nature of the anion ( Br ⁻, ClO ₄⁻, and tosylate) and are controlled by the free volume and the mobility of the pendant cation. By comparison of the results at constant free volume, it is shown that the charge density decreases with the increasing length of pendant PEO demonstrating that PEO acts only as a plasticizing agent. Best conductivity results (σ = 10⁻⁵ S cm⁻¹ at 60°C) are obtained with PEO side chains of molecular weight 350. With this sample, the conductivity in the presence of various amounts of added salt (LiTFSI) was studied. A best value of 10⁻⁴ S cm⁻¹ at 60°C is obtained with a molar ratio EO/Li of 10. It is shown that, over the range of examined concentrations (0.2–1.3 mol Li kg⁻¹), the reduced conductivity σ_r/c increases linearly with increasing salt concentration showing that the ion mobility increases continuously. Such behavior is quite unusual since in this concentration range a maximum is generally observed with PEO systems. To interpret this result and by analogy with the behavior of this type of polymer in solution, it is proposed that the conformation of these polymers in the solid state is segregated with the P4VP skeleton more or less confined inside the dense coils surrounded by the PEO side chains. Under the influence of the increasing salt concentration, this microphase separation vanishes progressively: The LiTFSI salt exchanges with the tosylate anions and acts as a miscibility improver agent. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2719–2728, 1997     

Investigation at the chain segmental level of the miscibility of poly(vinyl chloride)/atactic poly(methyl methacrylate) blends

We employed high‐resolution ¹³C cross‐polarization/magic‐angle‐spinning/dipolar‐decoupling NMR spectroscopy to investigate the miscibility and phase behavior of poly(vinyl chloride) (PVC)/poly(methyl methacrylate) (PMMA) blends. The spin–lattice relaxation times of protons in both the laboratory and rotating frames [T₁(H) and T_1ρ(H), respectively] were indirectly measured through ¹³C resonances. The T₁(H) results indicate that the blends are homogeneous, at least on a scale of 200–300 Å, confirming the miscibility of the system from a differential scanning calorimetry study in terms of the replacement of the glass‐transition‐temperature feature. The single decay and composition‐dependent T_1ρ(H) values for each blend further demonstrate that the spin diffusion among all protons in the blends averages out the whole relaxation process; therefore, the blends are homogeneous on a scale of 18–20 Å. The microcrystallinity of PVC disappears upon blending with PMMA, indicating intimate mixing of the two polymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2390–2396, 2001     

Thermokinetic studies of poly(<Emphasis Type="Italic">o</Emphasis>-toluidine) doped with perchloric acid

Thermokinetic parameters of the solid-state of poly(o-toluidine) (POT) doped with perchloric (HClO₄) acid was studied by thermogravimetric analysis (TG) and differential thermal analysis (DTA) under non-isothermal conditions. Molecular mechanics (MM) calculations suggest that the optimal geometric structure (OMG) of the HClO₄-doped POT is at least four orders of magnitude more stable than the molecular geometric (MG) structure. These calculations indicate that the potential energy (PE/kJ mol⁻¹) of the OMG is about four (1.09·10⁴) orders of magnitude lower than the MG structure of the same matrix. The empirical formula of the doped polymer is best represented by [POT-2HClO₄·2H₂O]_n as substantiate by elemental analysis and MM calculations. The full polymer decomposition and degradation were found to occur in three stages during the temperature increase. The decomposition activation energy (E _d) of HClO₄-doped POT matrix was calculated by employing different approximations. The heating rate (α) of the decomposition and the frequency factor (K _o) were calculated. A number of equations were used to evaluate the kinetic parameters. The mechanism of the degradation of the conducting polymer is explained on the basis of their kinetic parameters. A remarkable heating rate dependence of the decomposition rate was observed.     

Interdiffusion measurements of modified poly(arylether sulfone)s using nuclear reaction analysis

The interdiffusion and miscibility behavior of three different types of modified poly(arylether sulfone)s with deuterated poly(arylether sulfone) is studied by depth profiling using the nuclear reaction D(³He, α)p. The diffusion coefficients are found to be in the range of 10⁻¹⁵ and 10⁻¹⁴ cm²/s at 195°C. A random copolymer of poly(arylether sulfone) containing 4,4-bis-(4′-hydroxyphenyl)valeric acid units is only partially miscible with deuterated poly(arylether sulfone) when the comonomer content is 8.8 mol %, whereas blends with comonomer contents of 1.7 and 4.5 mol % are miscible as indicated by complete interdiffusion. The transition from miscibility to immiscibility is caused by repulsive interactions of copolymer segments and can be explained in terms of a mean-field theory of random copolymer blends. Also, poly(arylether sulfone)s grafted with 0.4 wt % maleic anhydride or having pyromellitic anhydride endgroups are miscible with deuterated poly(arylether sulfone)s. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2083–2091, 1997     

Thermal,crystallization, mechanical,and rheological characteristics of poly(trimethylene terephthalate)/poly(ethylene terephthalate) blends

Blends of poly(trimethylene terephthalate) (PTT) and poly(ethylene terephthalate) in the amorphous state were miscible in all of the blend compositions studied, as evidenced by a single, composition‐dependent glass‐transition temperature observed for each blend composition. The variation in the glass‐transition temperature with the blend composition was well predicted by the Gordon–Taylor equation, with the fitting parameter being 0.91. The cold‐crystallization (peak) temperature decreased with an increasing PTT content, whereas the melt‐crystallization (peak) temperature decreased with an increasing amount of the minor component. The subsequent melting behavior after both cold and melt crystallizations exhibited melting point depression behavior in which the observed melting temperatures decreased with an increasing amount of the minor component of the blends. During crystallization, the pure components crystallized simultaneously just to form their own crystals. The blend having 50 wt % of PTT showed the lowest apparent degree of crystallinity and the lowest tensile‐strength values. The steady shear viscosity values for the pure components and the blends decreased slightly with an increasing shear rate (within the shear rate range of 0.25–25 s^?1); those of the blends were lower than those of the pure components. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 676–686, 2004     

Simple route for synthesis of H‐shaped copolymers

The H‐shaped copolymers, [poly(L ‐lactide)]₂polystyrene [poly(L ‐lactide)]₂, [(PLLA)₂PSt(PLLA)₂] have been synthesized by combination of atom transfer radical polymerization (ATRP) with cationic ring‐opening polymerization (CROP). The first step of the synthesis is ATRP of St using α,α′‐dibromo‐p‐xylene/CuBr/2,2′‐bipyridine as initiating system, and then the PSt with two bromine groups at both chain ends (Br–PSt–Br) were transformed to four terminal hydroxyl groups via the reaction of Br–PSt–Br with diethanolamine in N,N‐dimethylformamide. The H‐shaped copolymers were produced by CROP of LLA, using PSt with four terminal hydroxyl groups as macroinitiator and Sn(Oct)₂ as catalyst. The copolymers obtained were characterized by ¹H NMR spectroscopy and gel permeation chromatography. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2794–2801, 2006