Molar Ratio Of Monomer Research Articles

Lipase-Catalyzed Synthesis of Aliphatic Polyesters via Copolymerization of Lactone, Dialkyl Diester, and Diol

Candida antarctica lipase (CALB) has been successfully used as catalyst for copolymerization of dialkyl diester with diol and lactone to form aliphatic polyesters. The polymerization reactions were performed using a two stage process: first stage oligomerization under low vacuum followed by second stage polymerization under high vacuum. Use of the two-stage process is required to obtain products with high molecular weights at high yields for the following reasons: (i) the first stage reaction ensures that the monomer loss via evaporation is minimized to maintain 1:1 diester to diol stoichiometric ratio, and the monomers are converted to nonvolatile oligomers; (ii) use of high vacuum during the second stage accelerates equilibrium transesterification reactions to transform the oligomers to high molecular weight polymers. Thus, terpolymers of omega-pentadecalactone (PDL), diethyl succinate (DES), and 1,4-butanediol (BD) with a M w of whole product (nonfractionated) up to 77000 and M w/ M n between 1.7 and 4.0 were synthesized in high yields (e.g., 95% isolated yield). A desirable reaction temperature for the copolymerizations was found to be around 95 degrees C. At 1:1:1 PDL/DES/BD monomer molar ratio, the resultant terpolymers contained equal moles of PDL, succinate, and butylene repeat units in the polymer chains. (1)H and (13)C NMR analyses were used to determine the polyester microstructures. The synthesized PDL-DES-BD terpolymers possessed near random structures with all possible combinations of PDL, succinate, and butylene units via ester linkages in the polymer backbone. Furthermore, thermal stability and crystallinity of a pure PDL-DES-BD terpolymer with 1:1:1 PDL to succinate to butylene unit ratio and M w of 85400 were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The copolyester was found to be a semicrystalline material with a T g of -34 degrees C and a T m of 64 degrees C, which degrades in a single weight loss step centered at T max = 408 degrees C.

Gel polymer electrolyte based on the synthesized co-polymer of poly(methyl methacrylate-maleic anhydride)

AbstractIn this study, poly(methyl methacrylate-maleic anhydride) (P(MMA-MAh)) was synthesized in toluene from methyl methacrylate (MMA) and maleic anhydride (MAh) monomers via free radical polymerization, in the presence of 2,2′-Azo-bis-isobutyronitrile (AIBN), as initiator at 80ºC for 8 h. The molar ratio of monomers was found to be 1 MAh:8 MMA using hydrolysis and titration. The molecular weight of co-polymer was determined to be of the order of 104 (g/mol) by gel permeation chromatography. The co-polymer was characterized using Fourier transform infrared and nuclear magnetic resonance spectroscopy. Thermogravimetric analysis indicated the initial decomposition temperature was ~270ºC. Differential scanning calorimetry indicated that the glass transition temperature was near 126ºC.Rectorite modified with benzyldimethyldodecylammonium chloride (OREC) was used as an additive to modify gel polymer electrolytes (GPEs) which consisted of P(MMA-MAh) used as a polymer matrix, propylene carbonate (PC) as a plasticizer and LiClO4 as the lithium ion source. X-ray diffraction analysis indicates that OREC can exfoliate well in GPEs when the amount of clay is suitable. The temperature dependence of the ionic conductivity of the resulting GPEs agreed well with the VTF (Vogel-Tamman-Fulcher) relation. OREC doses of 5 phr resulted in the greatest ionic conductivity. This OREC addition considerably improved the plasticized retention levels. As a consequence of OREC occupying the free volume space in the polymer matrix of GPEs, the bulk resistance of the GPEs was reduced and the glass transition temperature (Tg) increased.

Albumin molecularly imprinted polymer with high template affinity — Prepared by systematic optimization in mixed organic/aqueous media

An approach using systematic optimization for the formation of an albumin molecularly imprinted polymer (MIP), able to separate albumin from proteins in solution, has been prepared by imprinting albumin using a copolymer comprising 3-dimethylaminopropyl methacrylate and tetraethylene glycol dimethacrylate in a mole ratio of 1 to 8. Cytochrome c, lysozyme and myoglobin were used in competitive re-binding experiments to compete with the polymer's native template with all protein species present at 0.0004 g mL − 1 . The effects of: monomer to crosslinker mole ratio, polymerization temperature and time were investigated. It was found that the addition of water 6.04%, into the pre-polymerization albumin–monomer complex enhanced the adsorption capacity and selectivity of the resulting MIP from 2.18 × 10 − 3 to 6.02 × 10 − 3 g g-MIP − 1 and 83.5% to 98.7%, respectively. These results also showed that the MIP possessed high selectivity and adsorption capacity with respect to albumin in comparison with interfering species also present in solution. Polymerization temperature, time and the water content of the pre-polymerization mixture were all shown to have significant effects on the resulting albumin-MIP's performance. However, their influence on the polymer's affinity for the potentially interfering species was negligible. Additionally, higher polymerization temperatures (> 38 °C) and extended polymerization times (> 60 h) increased monomer conversion as determined by HPLC, but decreased the selectivity and adsorption capacity of the MIP. An optimized MIP, with very high selectivity and 6.37 × 10 − 3 g g-MIP − 1 template re-adsorption capacity was obtained using the following polymerization conditions: 0.125 mole ratio of monomer to crosslinker, 6.04 wt.% water content with respect to the mass of the monomer complex, 60 h polymerization time at 38 °C, and with 0.47% albumin in the pre-polymerization monomer complex. Finally, the functions of polymerization temperature, time and the significance of the water content in the albumin–monomer complex are also discussed.

Synthesis and characterization of a novel polymer based on anthracene moiety for organic thin film transistor

AbstractWe have designed and synthesized a new polymer, which could be used in the organic thin film transistor (OTFT). Poly[2,6‐bis(3′‐dodecythiophene‐2′‐yl)anthracene] (PDTAn), which is composed with anthracene moiety and dodecyl alkyl thiophene, was synthesized by oxidative polymerization using iron (III) chloride. The mole ratio of FeCl3 and monomer (4.2:1), keeping low temperature during the initiation reaction, amount of solvent, and dropping order were very important for oxidative polymerization without crosslinking. The molecular weight of the polymer (Mw) was measured to be 40,000 with 2.85 of polydispersity index by GPC. The physical and optical properties of the polymer were characterized by differential scanning calorimetry (DSC), cyclic voltammetry (CV), and optical absorption and photoluminescence (PL) spectroscopy. A field‐effect mobility of 1.1 × 10−4 cm2 V−1 S−1, a current on/off ratio of 105, and the Vth at −15.2 V had been obtained for OTFTs using this polymer semiconductor by solution coating. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5115–5122, 2008

Preparation and performance analysis of PE-supported P(AN- co-MMA) gel polymer electrolyte for lithium ion battery application

Copolymer, poly(acrylonitrile- co-methyl methacrylate) (P(AN- co-MMA)), was synthesized by solution polymerization with different mole ratios of monomers, acrylonitrile (AN) and methyl methacrylate (MMA). Polyethylene (PE) supported copolymer and gel polymer electrolyte (GPE) were prepared with this copolymer and their performances were characterized with FTIR, TGA, SEM, and electrochemical methods. It is found that the GPE using the PE-supported copolymer with AN to MMA = 4:1 (mole) exhibits an ionic conductivity of 2.06 × 10 −3 S cm −1 at room temperature. The copolymer is stable up to 270 °C. The PE-supported copolymer shows a cross-linked porous structure and has 150 wt% of electrolyte uptake. The GPE is compatible with anode and cathode of lithium ion battery at high voltage and its electrochemical window is 5.5 V (vs. Li/Li +). With the application of the PE-supported GPE in lithium ion battery, the battery shows its good rate and initial discharge capacity and cyclic stability.

Swelling behaviors of thermoresponsive hydrogels cross-linked with acryloyloxyethylaminopolysuccinimide

Based on a biodegradable cross-linker, acryloyloxyethylaminopolysuccinimide (AEA-PSI), a series of looser cross-linked poly(N-isopropylacrylamide-co-acrylic acid) [P(NIPAAm-co-AAc)] hydrogels were prepared, and their water content, swelling/deswelling kinetics, and the morphology of the gels were investigated. The swelling behaviors of AEA-PSI-cross-linked P(NIPAAm/AAc) hydrogels were investigated in Dulbecco’s phosphate-buffered saline (pH = 7.4), in the distilled water, and in the simulated gastric fluids (pH = 1.2), respectively. The water contents of the hydrogels were controlled by the monomer molar ratio of NIPAAm/AAc, swelling media, and the temperature. In the swelling kinetics, all the dried hydrogels exhibited fast swelling behavior, and the swelling ratios were influenced significantly by the amounts of AEA-PSI and AAc content. The deswelling kinetics of the hydrogel were independent of the content of AAc and cross-linker. Lastly, the morphology of the hydrogels was estimated by the field scan electron microscopy.

Chemical Oxidative Polymerization of Aminodiphenylamines

The course of oxidation of 4-aminodiphenylamine with ammonium peroxydisulfate in an acidic aqueous ethanol solution as well as the properties of the oxidation products were compared with those of 2-aminodiphenylamine. Semiconducting oligomers of 4-aminodiphenylamine and nonconducting oligomers of 2-aminodiphenylamine of weight-average molecular weights 3700 and 1900, respectively, were prepared by using an oxidant to monomer molar ratio of 1.25. When this ratio was changed from 0.5 to 2.5, the highest conductivity of oxidation products of 4-aminodiphenylamine, 2.5 x 10 (-4) S cm (-1), was reached at the molar ratio [oxidant]/[monomer] = 1.5. The mechanism of the oxidative polymerization of aminodiphenylamines has been theoretically studied by the AM1 and MNDO-PM3 semiempirical quantum chemical methods combined with the MM2 molecular mechanics force-field method and conductor-like screening model of solvation. Molecular orbital calculations revealed the prevalence of N prim-C10 coupling reaction of 4-aminodiphenylamine, while N prim-C5 is the main coupling mode between 2-aminodiphenylamine units. FTIR and Raman spectroscopic studies confirm the prevalent formation of linear N prim-C10 coupled oligomers of 4-aminodiphenylamine and suggest branching and formation of phenazine structural units in the oligomers of 2-aminodiphenylamine. The results are discussed with respect to the oxidation of aniline with ammonium peroxydisulfate, leading to polyaniline, in which 4-aminodiphenylamine is the major dimer and 2-aminodiphenylamine is the most important dimeric intermediate byproduct.

Synthesis of polymeric and hybrid nanoparticles for electroplating applications

Monodisperse polymeric particles with diameters in the range of 60–1400 nm were prepared by (emulsifier-free) emulsion polymerization and incorporated into electrolytic zinc coatings aiming to improve the corrosion resistance of electrogalvanized steel. Various types of polymeric nanoparticles were thus synthesized in order to assess the effect of the emulsifier, initiator and comonomer type on the particle morphology, stability and codeposition behavior. The polymerization experiments were carried out in laboratory-scale glass reactors and the most promising recipes were successfully scaled-up in a fully automated pilot-scale reactor. Replicates of some representative experiments, which were run both in lab and pilot-scale reactors, indicated excellent reproducibility of the polymerization process. Uniform, polymer-containing zinc coatings were produced by electrolytic codeposition of the nanoparticles from an acid zinc plating bath using a rotating disk electrode (RDE). Hybrid polystyrene/silica nanoparticles with increased silica content were also prepared via emulsifier-free emulsion polymerization, in the presence of an ultrafine aqueous silica sol, to be used in electrocoating applications. The effect of key process parameters, such as initial monomers molar ratio and pH on the size, morphology and silica content of the produced hybrid nanoparticles was investigated.

Gas permeability of fluorinated hyperbranched polyimide

AbstractThe gas permeability of carbon dioxide, oxygen and nitrogen for hyperbranched polyimide (HBPI) containing trifluoromethyl groups were investigated. The HBPIs were prepared by condensation polymerization of a triamine monomer, 1,3,5‐tris(2‐trifluoromethyl‐4‐aminophenoxy) benzene (TFAPOB) and a commercially available dianhydride monomer 1,4‐bis(3,4‐dicarboxyphenoxy) benzene dianhydride (HQDPA). With different monomer addition methods and different monomer molar ratios, amine terminated HBPI (AM‐HQDPA) and anhydride terminated HBPI (AD‐HQDPA) were obtained, subsequently, the trifluoromethylphenyl amine terminated HBPI (CF3‐HQDPA) was achieved by modifying the end groups of AD‐HQDPA with (3,5‐ditrifluoromethyl)aniline. The CF3‐HQDPA exhibited a good mechanical and thermal stability as well as AM‐HQDPA, and showed better gas permeabilities than that of AM‐HQDPA because of increase of free volume contributed by the bulky trifluoromethyl group introduced, but, the selectivity ofCF3‐HQDPA was lower than that of AM‐HQDPA. This result was consistent with the trade‐off relationship. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Synthesis and characterization of potassium humate–acrylic acid–acrylamide hydrogel

A novel potassium humate–acrylic acid–acrylamide (KHA–AA–AM) superabsorbent polymer was prepared from the reaction among leonardite potassium humate, acrylic acid and acrylamide by free radical initiating process using ammonium persulfate as the initiator and N, N′-methylene bisacrylamide as the crosslinker. Various effects of synthesis conditions on superabsorbent polymer were studied and the optimal reaction condition was obtained with crosslinker concentration 0.44–0.74 wt%, initiator concentration 1.12–2.22 wt%, n(KOH)/n(AA) 0.51–0.70, monomer concentration 10.95–12.59 wt%, graft reaction temperature 83 ± 1°C, monomer mole ratio of acrylic acid to acrylamide 1.42–2.30, and potassium humate content 17.54 wt%. Under the optimal conditions, the solution absorbency of KHA–AA–AM superabsorbent polymer to deionized water, tap water, 0.5% carbamide solution and 0.9% NaCl solution were 733–756, 161–284, 786–825, and 76–83 g/g, respectively.

Synthesis of Ultra-high Weight Average Molecular Mass of Poly-L-lactide

High purity in high yield L-lactide was prepared using a new purification method, and poly-L-lactide (PLLA) with ultra-high weight average molecular mass and narrow polydispersity index was synthesized by ring-opening polymerization. The effects of the purification method on the purity and yield of L-lactide were investigated, and the influences of initiator concentration, polymerization temperature and polymerization time on the weight average molecular mass of PLLA were also studied. A synthetic purification method involving a water bath and two times recrystallization could improve the purity of L-lactide to 100%. The yield of L-lactide reached 40.6% and increased 12.1% compared with the recrystallization method. Poly-L-lactide with a weight average molecular mass of about 102.4 × 104 and a polydispersity index of 1.16 was obtained when polymerization was conducted with molar ratio of monomer to initiator ([M]/[I]) of 12000 for 24 h at 140°C.

Properties and influence of hydrophobically associating polyacrylamide modified with 2-phenoxylethylacrylate

The properties of hydrophobically associating copolymer P(acrylamide (AM)/2-phenoxylethylacrylate (POEA)), composed of acrylamide and a small amount of POEA (⩽1.0 mol.%) as hydrophobe, were investigated in aqueous solution under various conditions. The results showed that the solution properties were strongly affected by the microstructure of copolymer. The copolymers (BP series) with hydrophobic microblocky structure exhibited large viscosity enhancement due to the intermolecular hydrophobic association, while that did not occur for the random copolymers (RP series). The hydrophobic association thickening behaviors were also remarkably dependent on the number and length of the hydrophobic block in polymer chain. Nonlinear viscosity relationship was found as increasing hydrophobe content and SMR (surfactant/hydrophobic monomer molar ratio), and a maximum appeared at the middle position as a result of the competitive effect between inter- and intra- molecular hydrophobic associations. Solution properties were further studied as a function of the polymer concentration, salinity, temperature and shear rate. The block copolymers show high salt tolerance and shear thinning as well as recovery after shear.

Synthesis and Properties of Multiallyl Maleate Resins from Epoxy Formaldehyde Resins

Formaldehyde resins at various molar ratios of monomers (aniline/o-cresol/cyclohexanone) were synthesized under acid catalysis. The resultant resins were reacted with a large excess of epichlorohydrin, and multifunctional epoxy formaldehyde resins were obtained. These resins were reacted with monoallyl ester of maleic acid in the presence of benzyltriethylammonium bromide as catalyst, and multiallyl maleate resins were obtained. The resins were characterized by elemental analysis and by spectroscopic methods (IR and NMR). The curing and decomposition behavior of cross-linked resins were studied by DSC and TGA techniques. The presence of allyl maleate as pendant groups on polymeric chains confers on them the improvement of the possibilities for obtaining thermosetting resin systems based on bismaleimide derivatives. The cross-linked products showed good thermal properties, high glass transitions, and low water absorption.

Inorganic Phosphate Binds to the Empty Nucleotide Binding Pocket of Conventional Myosin II

In muscle inorganic phosphate strongly decreases force generation in the presence of millimolar MgATP, whereas phosphate slows shortening velocity only at micromolar MgATP concentrations. It is still controversial whether reduction in shortening velocity by phosphate results from phosphate binding to the nucleotide-free myosin head or from binding of phosphate to an actomyosin-ADP state as postulated for the inhibition of force generation by phosphate. Because most single-molecule studies are performed at micromolar concentrations of MgATP where phosphate effects on movement are rather prominent, clarification of the mechanisms of phosphate inhibition is essential for interpretation of data in which phosphate is used in single molecule studies to probe molecular events of force generation and movement. In in vitro assays we found that inhibition of filament gliding by inorganic phosphate was associated with increased fragmentation of actin filaments. In addition, phosphate did not extend dwell times of Cy3-EDA-ATP (2'(3')-O-[[2-[[6-[2-[3-(1-ethyl-1,3-dihydro-3,3-dimethyl-5-sulfo-2H-indol-2-ylidene)-1-propenyl]-3,3-dimethyl-5-sulfo-3H-indolio]-1-oxohexyl]amino]ethyl]carbamoyl]ATP) but reduced the number of Cy3-signals per field of view, approaching 50% at phosphate concentrations of 1-2 mM. Apparently, inhibition of movement does not result from binding of phosphate to an actomyosin-ADP intermediate as proposed by Hooft and coworkers (Hooft, A. M., Maki, E. J., Cox, K. K., and Baker, J. E. (2007) Biochemistry 46, 3513-3520) but, rather, from forming a strong-binding actomyosin-phosphate intermediate.

Analysis of the interaction using FTIR within the components of OREC composite GPE based on the synthesized copolymer matrix of P(MMA-MAh)

Poly(methyl methacrylate-maleic anhydride) (P(MMA-MAh)) has been synthesized from methyl methacrylate (MMA) and maleic anhydride (MAh) monomers. The molar ratio of monomers was found to be 1MAh:8MMA. The molecular weight of copolymer was determined in the order 104 (g/mol).Rectorite modified with dodecyl benzyl dimethyl ammonium chloride (OREC) was used as a filler additive to modify gel polymer electrolytes (GPEs) which consisted of P(MMA-MAh) used as polymer matrix, propylene carbonate (PC) as a plasticizer and LiClO4 as lithium ion producer. Characterization of interaction of CO in PC and copolymer with Li+ and OH group on OREC surface has been thoroughly examined using FTIR. The quantitative analysis of FTIR shows that the absorptivity coefficient a of copolymer/LiClO4, PC/LiClO4, PC/OREC and copolymer/OREC is 0.756, 0.113, 0.430 and 0.602, respectively, which means that the Li+ or OH bonded CO is more sensitive than free CO in FTIR spectra. The limit value of bonded CO equivalent fraction of copolymer/LiClO4, PC/LiClO4, PC/OREC and copolymer/OREC is 55, 94, 57 and 26%, respectively, which implies that all the interaction within the components is reversible and the intensity of interaction is ordered as PC/LiClO4, PC/OREC, copolymer/OREC and copolymer/LiClO4.

Biocatalytic hydrogels by template polymerization

AbstractNovel ionizable hydrogels were prepared from poly(acrylic acid) and dimethylaminoethyl methacrylate monomer employing template polymerization technique as an alternative to traditional physical and chemical crosslinking. The mode of interaction, as proved by Fourier Transform Infrared Spectroscopy (FTIR), was multiple H‐bonding between the tertiary amino group of the monomer and the carboxylic groups of the polymer. The hydrogels represented suitable matrices for enzyme immobilization. The effect of varying the polymer–monomer molar ratio on the swelling kinetics and parameters was investigated. The dynamic swelling isotherm exhibited a Fickian mode of penetrant sorption and a plateau that increases with the amino group content. A polymer complex of molar ratio (polymer:monomer) 0.5:0.8 had a weight swelling ratio of 10 and 7 at pHs 3 and 8, respectively. The proven pH sensitivity together with the amphoteric character of these hydrogels make them good candidates for another bioapplication such as oral delivery systems of therapeutic peptides and proteins. The structural integrity of the hydrogels was proved by their swelling reversibility. β‐Galactosidase, as an acidic model enzyme, was immobilized covalently on the synthesized hydrogels. The maximum enzyme velocity (Vmax) was enhanced to 19 µmol/min/mg, for polycomplex of molar ratio 0.5:0.8, compared with 3.2 µmol/min/mg for the free enzyme. Copyright © 2008 John Wiley & Sons, Ltd.

SYNTHESIS, CHARACTERIZATION AND NANOPARTICLE FORMATION OF STAR-SHAPED POLY(L-LACTIDE) WITH SIX ARMS

Well-defined star-shaped poly(L-lactide) with six arms (sPLLA) was synthesized via the ring-opening polymerization of L-lactide using dipentaerythritol as initiator and stannous octoate as catalyst in bulk at 125°C. The effects of molar ratios of both monomer to initiator and monomer to catalyst on the molecular weights of as-synthesized sPLLA polymers were in detail investigated. The molecular weights of sPLLA polymers linearly increased with the molar ratio of monomer to initiator, and the molecular weight distribution was narrow (Mw/Mn = 1.04–1.12). However, the molar ratio of monomer to catalyst had no apparent influence on the polymer molecular weight. Moreover, the maximal melting point, the crystallization temperature, and the degree of crystallinity of sPLLA polymers increased with the increasing molecular weight, meanwhile they exhibited a spherulitic morphology. Furthermore, spherical nanoparticles (less than 100 nm) could be generated by direct injection of sPLLA solutions into distilled water, and the average size of nanoparticles could be adjusted through both the macromolecular architecture and the polymer molecular weight, respectively.

Self-assembly synthesis of hollow, core–shell and solid soluble oligo(3,4-ethylenedioxythiophene)s microspheres in a mixed solvent

Three different kinds of the mixture of oligo(3,4-ethylenedioxythiophene)s (oligo-EDOTs) microstructures—hollow microspheres with a hole on the surface, cell-like microspheres with core–shell structures and matte solid microspheres were successfully synthesized using FeCl 3·6H 2O as an oxidant in acetone/water mixed solvent. These three microstructures were obtained only through simply adjusting the volume ratio of acetone and water, the molar ratio of monomer and oxidant or the concentration of the monomer 3,4-ethylenedioxythiophene, respectively, and confirmed by SEM and TEM images. Unlike the insolubility of PEDOT, these oligo-EDOTs microspheres could be dissolved in organic solvent, such as THF, DMF and DMSO. The formation of them might be due to the self-assembly that occurred simultaneously with the oxidation of EDOT monomer on the surface of the well-dispersed EDOT droplets which acted as templates and were formed by the induction of mixed solvent.

Nanoflakes to nanorods and nanospheres transition of selenious acid doped polyaniline

Morphology transition of selenious acid doped polyaniline from nanoflakes to nanorods and nanospheres was explored by changing the selenious acid–aniline (dopant–monomer) mole ratio in the aniline polymerization. The transition of polyaniline nanospheres to nanorods occurred when the dopant–monomer mole ratio was between 1 and 0.5. The formation of polyaniline nanorods was dominant when the dopant–monomer mole ratio is 0.5. At mole ratio 0.5, nanorods were obtained with the diameter at around 150nm. At mole ratio 1, both the nanorods and nanospheres were formed and formation of the nanosphere is favored when the mole ratio is more than 1. When the mole ratio was low (0.125–0.03), polyaniline showed flakes like morphology. The morphology transition was studied by scanning electron microscopy and the molecular structure was confirmed by X-ray diffraction, FTIR and UV–vis spectroscopy. A simple and practical route to synthesize polyaniline nanostructures was demonstrated using selenious acid as effective dopant. The mechanism governing the formation of the polyaniline nanostructures is discussed.

Synthesis and characterization of poly(benzodithiophene) derivative for organic thin film transistors

AbstractPoly{2,6‐bis(3‐dodecylthiophen‐2‐yl) benzo[1,2‐b;4,5‐b′]dithiophene} (PTBT) was synthesized, via oxidative polymerization by oxidative agent (FeCl3). The mole ratio of FeCl3 and monomer (3.5:1), and keeping low temperature during the dropping of diluted catalyst were very important for the polymerization without crosslinking. The PTBT was confirmed by 1H NMR, FTIR spectra, and elemental analysis. The PTBT has very good solubility in organic solvents such as chloroform, tetrahydrofuran, etc, and good thermal stability with Tg of 164 °C. The PTBT shows UV‐optical absorption at 406 nm and photoluminescence (PL) spectroscopy at 504 nm in a film. The highest occupied molecular orbital (HOMO) energy of the polymer is −5.71 eV by measuring cyclic voltammetry (CV). A solution‐processed polymer thin film transistor device shows a mobility of 3 × 10−5 – 8 × 10−5 cm2 V−1 s−1, and an on/off current ratio of 104. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5277–5284, 2007