Synthesis and nonlinear properties of poly[1,4‐bis(4‐alkylpyridinium)butadiyne triflate]

1,4‐Bis(4‐alkylpyridinium)butadiyne triflate ( 2a and 2b ) that was prepared by the reaction of 1,4‐bis(4‐pyridyl)butadiyne ( 1 ) with alkyl trifluoro‐methanesulfonate, was found to grow into a large crystal as a result of the quaternized structure. The thermal treatment of 2a and 2b gave rise to 1,4‐addition polymerization to yield the polydiacetylene. The third‐order nonlinear optical susceptibility [χ⁽³⁾] of the polymer was determined by the femto‐second Z‐scan method to exhibit the remarkable high value of 1.1 × 10^?11 esu at 650 nm. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3686–3691, 2001     

Copolymerization of poly(vinyl alcohol)‐graft‐poly(1,4‐dioxan‐2‐one) with designed molecular structure by a solid‐state polymerization method

Poly(vinyl alcohol)‐graft‐poly(1,4‐dioxan‐2‐one) (PVA‐g‐PPDO) with designed molecular structure was synthesized by a solid‐state polymerization. The solid‐state copolymerization was preceded by a graft copolymerization of PDO initiated with PVA as a multifunctional initiator, and Sn (Oct)₂ as a coininitiator/catalyst in a homogeneous molten state. The polymerization temperature was then decreased and the copolymerization was carried out in a solid state. The products prepared by solid‐state polymerization were characterized by ¹H NMR and DSC, and were compared with those synthesized in the homogeneous molten state. The degree of polymerization (D_p), degree of substitution (D_s), yield and the average molecular weight of the graft copolymer with different molecular structure were calculated from the ¹H NMR spectra. The results show that the crystallization process during the solid‐state polymerization may suppress the undesirable inter‐ or intramolecular side reactions, then resulting in a controlled molecular structure of PVA‐g‐PPDO. The results of DSC measurement show that the molecular structures determine the thermal behavior of the PVA‐g‐PPDO. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3083–3091, 2006     

Cationic addition polymerization of 1,4‐dioxene using gacl3 as lewis acid catalyst: Long‐lived species‐mediated polymerization

Effective cationic addition polymerization of 1,4‐dioxene, a six‐membered cyclic olefin with two oxygen atoms adjacent to the double bond, was performed using a simple metal halide catalyst system in dichloromethane. The polymerization was controlled when the reaction was conducted using GaCl₃ in conjunction with an isobutyl vinyl ether–HCl adduct as a cationogen at –78°C to give polymers with predetermined molecular weights and relatively narrow molecular weight distributions. The long‐lived properties of the propagating species were further confirmed by a monomer addition experiment and the analyses of the product polymers by ¹H NMR and MALDI–TOF–MS. Although highly clean propagation proceeded, the apparent rate constant changed during the controlled cationic polymerization of 1,4‐dioxene. The reason for the change was discussed based on polymerization results under various conditions. The obtained poly(1,4‐dioxene) exhibited a very high glass transition temperature (T_g) of 217°C and unique solubility. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Photocurable and thermally stable polymers based on 1,4‐pentadien‐3‐one‐1‐p‐hydroxyphenyl‐5‐p‐phenyl methacrylate: Copolymerization with ethyl acrylate

1,4‐Pentadien‐3‐one‐1,5‐bis(p‐hydroxyphenyl) (PBHP) was prepared by reacting p‐hydroxybenzaldehyde and acetone in the presence of an acid catalyst. 1,4‐Pentadiene‐3‐one‐1‐p‐hydroxyphenyl‐5‐p‐phenyl methacrylate (PHPPMA) monomer was prepared by reacting PBHP dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in the presence of triethylamine. A free‐radical solution polymerization technique was used for synthesizing homo‐ and copolymers of different feed compositions of PHPPMA and ethyl acrylate (EA) in EMK as a solvent with benzoyl peroxide as a free‐radical initiator at 70 ± 1 °C. All the polymers were characterized with IR and ¹H NMR techniques. The compositions of the copolymers were determined with the ¹H NMR technique. The copolymer reactivity ratios were evolved with Kelen–Tudos (EA = 1.25 and PHPPMA = 0.09) and extended Kelen–Tudos (EA = 1.30 and PHPPMA = 0.09) methods. Q (0.48) and e (1.68) values for the new monomer (PHPPMA) were calculated with the Alfrey–Price method. UV absorption spectra for poly(PHPPMA) showed two absorption bands at 302 and 315 nm. The photocrosslinking properties of the polymer samples were examined with the solvent method. Thermal analyses of the polymers were performed with the thermogravimetric‐differential thermogravimetric technique. First, the decomposition temperatures started for poly(PHPPMA), copoly(EA‐PHPPMA) (62:38), and copoly(EA‐PHPPMA) (41:59) were at 350, 410, and 417 °C, respectively. A gel permeation chromatographic method was used for determining the polymer molecular weights (weight‐average molecular weight: 2.67 × 10⁴ and number‐average molecular weight: 1.41 × 10⁴) and polydispersity index (1.89). The solubility of the monomer and the copolymers occurred at 30 °C with solvents having different polarities. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1632–1640, 2003     

Synthesis of metal‐free poly(1,4‐dioxan‐2‐one) by enzyme‐catalyzed ring‐opening polymerization

To avoid the harmful effects of metallic residues in poly(1,4‐dioxan‐2‐one) (PPDO) for medical applications, the enzymatic polymerization of 1,4‐dioxan‐2‐one (PDO) was carried out at 60 °C for 15 h with 5 wt % immobilized lipase CA. The lipase CA, derived from Candida antarctica, exhibited especially high catalytic activity. The highest weight‐average molecular weight (M_w = 41,000) was obtained. The PDO polymerization by the lipase CA occurred because of effective enzyme catalysis. The water component appeared to act not only as a substrate of the initiation process but also as a chain cleavage agent. A slight amount of water enhanced the polymerization, but excess water depressed the polymerization. PPDO prepared by enzyme‐catalyzed polymerization is a metal‐free polyester useful for medical applications. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1560–1567, 2000     

Dependence of the luminescent properties and chain length of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylene vinylene] on the formation of cis‐vinylene bonds during Gilch polymerization

The presence of cis‐vinylene bonds in Gilch‐polymerized poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylene vinylene] is reported. Through fractionation, species with a weight‐average molecular weight of less than 37,000 exhibited an abnormal blueshift of photoluminescence spectra in toluene solutions, and this was attributed to the presence of cis‐vinylene bonds, as verified by NMR spectroscopy. Surprisingly, the fractionated species (～1 wt %) with a weight‐average molecular weight of 5000 were mostly linked by the cis‐vinylene bonds. The concentration decreased with the molecular weight until a molecular weight of 37,000 was reached; at that point, the polymer chains contained mainly trans‐vinylene bonds. Obviously, the formation of cis‐vinylene bonds strongly inhibited the growth of polymer chains during Gilch polymerization. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2520–2526, 2005     

Stereospecific and molecular weight‐controlled polymerization of 1,3‐butadiene with Co(acac)3‐MAO catalyst

The polymerization of butadiene (Bd) with Co(acac)₃ in combination with methylaluminoxane (MAO) was investigated. The polymerization of Bd with Co(acac)₃‐MAO catalysts proceeded to give cis‐1,4 polymers (94 – 97%) bearing high molecular weights (40 × 10⁴) with relatively narrow molecular weight distributions (M_w's/M_n's). The molecular weight of the polymers increased linearly with the polymer yield, and the line passed through an original point. The polydispersities of the polymers kept almost constant during reaction time. This indicates that the microstructure and molecular weight of the polymers can be controlled in the polymerization of Bd with the Co(acac)₃‐MAO catalyst. The effects of reaction temperature, Bd concentration, and the MAO/Co molar ratio on the cis‐1,4 microstructure and high molecular weight polymer in the polymerization of Bd with Co(acac)₃‐MAO catalyst were observed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2793–2798, 2001     

Ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by lanthanum isopropoxide in bulk

Lanthanum isopropoxide (La(OiPr)₃) has been synthesized and employed for ring‐opening polymerization of 1,4‐dioxan‐2‐one in bulk as a single‐component initiator. The influences of reaction conditions such as initiator concentration, reaction time, and reaction temperature on the polymerization were investigated. The kinetics indicated that the polymerization is first‐order with respect to the monomer concentration. The Mechanistic investigations according to ¹H NMR spectrum analysis demonstrated that the polymerization of PDO proceeded through a coordination‐insertion mechanism with a rupture of the acyl‐oxygen bond of the monomer rather than the alkyl‐oxygen bond cleavage. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5214–5222, 2008     

Rapid ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by titanium alkoxides

Ring‐opening polymerization of 1,4‐dioxan‐2‐one in bulk was initiated by three titanium alkoxides, titanium dichlorodiisopropoxide (TiCl₂(OiPr)₂), titanium chlorotriisopropoxide (TiCl(OiPr)₃), and titanium tetraisopropoxide (Ti(OiPr)₄). The results indicate that the polymerization rate increased with number of OiPr groups in the initiator. High conversion of monomer (90%) and high molecular weight (11.9 × 10⁴ g/mol) of resulting polymer can be achieved in only 5 min at 60 °C with Ti(OiPr)₄ as an initiator. Analysis on nuclear magnetic resonance (NMR) spectra suggests the initiating sites for TiCl₂(OiPr)₂, TiCl(OiPr)₃, and Ti(OiPr)₄ to be 1.9, 2.6, and 3.8, respectively. Coordination‐insertion mechanism for the polymerization via cleavage of the acyl–oxygen bonds of the monomer was proved by NMR investigation. Kinetic studies indicate that polymerization initiated by Ti(OiPr)₄ followed a first‐order kinetics, with an apparent activation energy of 33.7 kJ/mol. It is noteworthy that this value is significantly lower than earlier reported values with other catalysts, namely La(OiPr)₃ (50.5 kJ/mol) and Sn(Oct)₂ (71.8 kJ/mol), which makes it an attractive catalyst for reactive extrusion polymerization. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and hydrolytic degradation of a random copolymer derived from 1,4‐dioxan‐2‐one and glycolide

Novel biodegradable copolymers, poly(1,4‐dioxan‐2‐one‐co‐glycolide) [P(DON‐co‐GA)] containing a high proportion of 1,4‐dioxan‐2‐one (DON), were synthesized by copolymerizations of DON and glycolide (GA) at 120 °C for 16 h using stannous octoate as catalyst. Chemical composition and microstructural variation of the resulting copolymer were investigated by ¹H‐ and ¹³C NMR and thermal properties by differential scanning calorimetry (DSC). From the ¹³C NMR spectra, it was observed that, apart from the expected preponderance of DON sequences, the minor component, GA, was indeed distributed at various points along the copolymer chain rather than incorporated as distinct blocks, which is consistent with a random sequence distribution. This view also was supported by the DSC results, which showed that most copolymers were amorphous except for one with a relatively high fraction of DON. The conclusion that it was a random structure rather than a statistical copolymer is discussed, using the theories about the mechanism of this type of polymerization in current as a reference. P(DON‐co‐GA) films were prepared by casting the copolymer solution in hexafluoroisopropanol (HFIP) with two concentrations of the polymeric solution (10 and 25 wt %). The in vitro hydrolytic degradation behaviors of these films were studied in phosphate buffer solution (pH = 7.4) at 37 °C and characterized by DSC, scanning electron microscopy, weight loss, and change in inherent viscosity. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2558–2566, 2004     

New biodegradable polymers from renewable sources: Polyester‐carbonates based on 1,3‐propylene‐co‐1,4‐cyclohexanedimethylene succinate

α,ω‐Dihydroxy‐terminated copolymeric oligomers of a 1,3‐propylene/1,4‐cyclohexanedimethylene succinate structure were obtained by the thermal polycondensation of 1,3‐propanediol/1,4‐cyclohexanedimethanol/succinic acid mixtures. They were subsequently chain‐extended via phosgene synthesis to high molecular weight aliphatic/alicyclic copolyester‐carbonates. These new polymers, besides having a biodegradable backbone, originate from two monomers, namely, 1,3‐propanediol and succinic acid, which can be obtained by renewable sources. Therefore, they have a potential as environmentally friendly materials. All synthesized materials were characterized in reference to their molecular structure by ¹H NMR and ¹³C NMR. Their molecular weights and molecular weight distributions were determined by size exclusion chromatography, and their main thermal properties were measured by DSC. Spectroscopic characterizations were in full agreement with the proposed structures. 1,4‐Cyclohexanedimethanol was used as a diol comonomer to improve the overall thermal properties of poly(1,3‐propylene succinate). The results of the characterization performed show that the initial expectations were only partially satisfied. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2508–2519, 2001     

Oxidation polymerization of a charge‐transfer complex of 2,6‐bis(2‐thienyl)‐1,4‐dithiafulvene with 7,7,8,8‐tetracyanoquinodimethane

A π‐conjugated poly(α‐dithienylen‐dithiafulvene) ( 2 ) was obtained by the oxidation polymerization of 2,6‐bis(2‐thienyl)‐1,4‐dithiafulvene ( 1 ) as a dithiafulvene monomer derived from 4‐(2‐thienyl)‐1,2,3‐thiadiazole. When a solution of 1 in CHCl₃ was added to a stirred solution of FeCl₃ in CHCl₃, only the low‐molecular‐weight product 2 was obtained. The mixture was stirred for 15 h with an N₂ flow. The polymerization at higher temperatures resulted in polymers with large insoluble fractions. A higher molecular weight polymer was obtained by the oxidation polymerization of a charge‐transfer complex of 1 with 7,7,8,8‐tetracyanoquinodimethane (compound 3 ). In contrast to 2 , polymer 4 was readily soluble in dimethyl sulfoxide, dimethylformamide, and acetone and partially soluble in tetrahydrofuran and methanol and had a larger molecular weight (peak top molecular weight = 37,000). The conductivity of polymer 4 was 3 orders of magnitude larger than that of polymer 2 . © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6592–6598, 2005     

High‐temperature elastomers from silarylene‐siloxane‐diacetylene linear polymers

The syntheses and characterization of linear silarylene‐siloxane‐diacetylene polymers 3a–c and their thermal conversion to crosslinked elastomeric materials 4a–c are discussed. Inclusion of the diacetylene unit required synthesis of an appropriate monomeric species. 1,4‐Bis(dimethylaminodimethylsilyl)butadiyne [(CH₃)₂N? Si(CH₃)₂? C?C? C?C? (CH₃)₂Si? N(CH₃)₂] 2 was prepared from 1,4‐dilithio‐1,3‐butadiyne and 2 equiv of dimethylaminodimethylchlorosilane. The linear polymers were prepared via polycondensation of 2 with a series of disilanol prepolymers. The low molecular weight silarylene‐siloxane prepolymers 1a–c (terminated by hydroxyl groups) were synthesized via solution condensation of an excess amount of 1,4‐bis(hydroxydimethylsilyl)benzene with bis(dimethylamino)dimethylsilane. The linear polymers were characterized by ¹H and ¹³C NMR, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis (TGA), and DSC. The elastomers exhibited long‐term oxidative stability up to 330 °C in air as determined by TGA. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 88–94, 2002     

1,4‐Dilithio‐1,1,4,4‐tetraphenylbutane in diethyl ether: An effective initiator for the living anionic polymerization of dienes

The anionic polymerization of butadiene initiated with 1,4‐dilithio‐1,1,4,4‐tetraphenylbutane (LiTPB) in diethyl ether (DEE) gives polybutadiene (PBD) with high 1,2 content (>70%), narrow polydispersities (1.04 < M_w/M_n < 1.20), and predicted molecular weights. In THF, this polymerization does not work very well. After removal of DEE and addition of THF, the PBD dianion is end capped quantitatively by addition of 1,1‐diphenylethylene (DPE) to give the diphenylalkyl end capped PBD dianion. Subsequent addition of methyl methacrylate at low temperatures results in the formation of well‐defined PMMA‐b‐PBD‐b‐PMMA triblock copolymers. The results are accounted for by taking into account the effects of Li ion solvation on the BD initiation and end capping of the PBD anion by DPE. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2198–2206, 2009     

Chain composition dependence of luminescence properties for copolymers of 2‐methoxy‐5‐2′‐ethyl‐hexyloxy‐1,4‐phenylenevinylene and 2,3‐diphenyl‐5‐octyl‐1,4‐phenylenevinylene

The copolymers of 2‐methoxy‐5‐2′‐ethyl‐hexyloxy‐1,4‐phenylenevinylene (MEH‐PV) and 2,3‐diphenyl‐5‐octyl‐1,4‐phenylenevinylene were prepared via the Gilch route with their chain compositions and the reactivity ratios of the monomers estimated by ¹H NMR spectroscopy. The results indicated that the copolymers tended to form an alternative copolymer as the feed ratio of the monomers closed to one‐half. When an individual copolymer solution in tetrahydrofuran was spun‐cast to form a film, the MEH‐PV units were able to attract the like units from the adjacent chains. As a result, the ultraviolet–visible absorption spectrum of the alternative copolymer in film form was broader than the spectra of those with different compositions. The photoluminescence spectra of the copolymers in film form exhibited the characteristic shoulder of poly(2‐methoxy‐5‐2′‐ethyl‐hexyloxy‐1,4‐phenylenevinylene), even though the content of MEH‐PV units was not great enough for the formation of repeat units in sequence. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2180–2186, 2003     

Anionic polymerization of 4‐phenyl‐1‐buten‐3‐yne derivatives bearing electron‐withdrawing groups

The anionic polymerization of derivatives of 4‐phenyl‐1‐buten‐3‐yne was carried out to investigate the effect of substituents on the polymerization behavior. The polymerization of 4‐(4‐fluorophenyl)‐1‐buten‐3‐yne and 4‐(2‐fluorophenyl)‐1‐buten‐3‐yne in tetrahydrofuran at −78 °C with n‐BuLi/sparteine as an initiator gave polymers consisting of 1,2‐ and 1,4‐polymerized units in quantitative yields with ratios of 80/20 and 88/12, respectively. The molecular weights of the polymers were controlled by the ratio of the monomers to n‐BuLi, and the distribution was relatively narrow (weight‐average molecular weight/number‐average molecular weight < 1.2), supporting the living nature of the polymerization. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1016–1023, 2001     

Influence of tertiary diamines on the synthesis of high‐molecular‐weight poly(1,3‐cyclohexadiene)

The living synthesis of poly(1,3‐cyclohexadiene) was performed with an initiator adduct that was synthesized from a 1:2 (mol/mol) mixture of N,N,N′,N′‐tetramethylethylenediamine (TMEDA) and n‐butyllithium. This initiator, which was preformed at 65 °C, facilitated the synthesis of high‐molecular‐weight poly(1,3‐cyclohexadiene) (number‐average molecular weight = 50,000 g/mol) with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight = 1.12). A plot of the kinetic chain length versus the time indicated that termination was minimized and chain transfer to the monomer was eliminated when a preformed initiator adduct was used. Chain transfer was determined to occur when the initiator was generated in situ. The polymerization was highly sensitive to both the temperature and the choice of tertiary diamine. The use of the bulky tertiary diamines sparteine and dipiperidinoethane resulted in poor polymerization control and reduced polymerization rates (7.0 × 10⁻⁵ s⁻¹) in comparison with TMEDA‐mediated polymerizations (1.5 × 10⁻⁴ s⁻¹). A series of poly(1,3‐cyclohexadiene‐block‐isoprene) diblock copolymers were synthesized to determine the molar crossover efficiency of the polymerization. Polymerizations performed at 25 °C exhibited improved molar crossover efficiencies (93%) versus polymerizations performed at 40 °C (80%). The improved crossover efficiency was attributed to the reduction of termination events at reduced polymerization temperatures. The microstructure of these polymers was determined with ¹H NMR spectroscopy, and the relationship between the molecular weight and glass‐transition temperature at an infinite molecular weight was determined for polymers containing 70% 1,2‐addition (150 °C) and 80% 1,4‐addition (138 °C). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1216–1227, 2005     

Photoinduced controlled/living free‐radical polymerization of 4‐methacryloyl‐1,2,2,6,6‐pentamethyl‐piperidenyl

The photoinduced solution polymerization of 4‐methacryloyl‐1,2,2,6,6‐pentamethyl‐piperidinyl (MPMP), used as a reactive hindered amine piperidinol derivative, was performed. The obtained MPMP homopolymer had a very narrow molecular weight distribution (1.06–1.39) according to gel permeation chromatography. The number‐average and weight‐average molecular weights increased linearly with the monomer conversion, this being characteristic of controlled/living free‐radical polymerizations. Electron spin resonance signals were detected in the MPMP homopolymer and in a polymer mixture solution, and they were assigned to nitroxide radicals, which were bound to the polymer chains and persisted at a level of 10^?9 mol/L during the polymerization. Instead of the addition of mediated nitroxide radicals such as 2,2,6,6‐tetramethyl‐piperidinyl‐1‐oxy (TEMPO), those radicals (>N? O ·) were formed in situ during the photopolymerization of MPMP, and so the reaction mechanism was understood as being similar to that of TEMPO‐mediated controlled/living free‐radical polymerization. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2659–2665, 2004     

Synthesis and opto‐electrical properties of dendron‐containing poly(2,3‐diphenyl‐1,4‐phenylenevinylene) derivatives

A new series of poly(2,3‐diphenyl‐1,4‐phenylenevinylene) derivatives containing dendritic side groups were synthesized. Different generations of dendrons were integrated on the pendant phenyl ring to investigate their effect on optical and electrical properties of final polymers. Homopolymers can not be obtained via the Gilch polymerization because of sterically bulky dendrons. By controlling the feed ratio of different monomers during polymerization, dendron‐containing copolymers with high molecular weights were obtained. The UV–vis absorption and photoluminescent spectra of the thin films are pretty close; however, quantum efficiency is significantly enhanced with increasing the generation of dendrons. The electrochemical analysis reveals that hole‐injection is also improved by increasing dendritic generation. Double‐layer light‐emitting devices with the configuration of ITO/PEDOT:PSS/polymer/Ca/Al were fabricated. High generation dendrons bring benefit of improved device performance. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3440–3450, 2007     

Investigation of catalyst‐transfer condensation polymerization for synthesis of poly(p‐phenylenevinylene)

Kumada‐Tamao coupling polymerization of 1,4‐dialkoxy‐2‐bromo‐5‐(2‐chloromagnesiovinyl)benzene ( 1 ) and 1,4‐dialkoxy‐2‐(2‐bromovinyl)‐5‐chloromagnesiobenzene ( 2 ) with a Ni catalyst and Suzuki‐Miyaura coupling polymerization of 2‐{2‐[(2,5‐dialkoxy‐4‐iodophenyl)]vinyl}‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane ( 3 ), its bromo counterpart 4 , and 2,5‐dialkoxy‐4‐(2‐bromovinyl)phenylboronic acid ( 5 ) with a Pd initiator were investigated under catalyst‐transfer condensation polymerization conditions for the synthesis of well‐defined poly(p‐phenylenevinylene) (PPV). The Kumada‐Tamao polymerization of vinyl Grignard‐type monomer 1 with Ni(dppp)Cl₂ at room temperature did not proceed, whereas aryl Grignard‐type monomer 2 afforded oligomers of low molecular weight. Matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectra of the polymer obtained from 2 implied that the Grignard end group reacted with tetrahydrofuran to terminate polymerization. On the other hand, Suzuki‐Miyaura polymerization of vinyl boronic acid ester type monomers 3 and 4 and phenylboronic acid type monomer 5 with a Pd initiator and aqueous KOH at ?20 °C to room temperature yielded the corresponding PPV with high molecular weight within a few minutes. However, the molecular weight distribution was broad, and MALDI‐TOF mass spectra showed the peaks of polymers bearing no initiator unit at the chain end, as well as those of polymers with the initiator unit. These results indicated that intermolecular chain transfer of the Pd catalyst occurred. Dehalogenation and disproportionation of the growing end also took place as side reactions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2643‐2653