Synthesis and polymerizability of CN monomers

The synthesis and polymerizability of imine C?N monomers is surveyed. The investigated imines were either far more reactive than similarly substituted C?C or C?O monomers, or too stable to polymerize. Imines with electron‐attracting substituents on N favor polymerization by anionic mechanism, but led only to low molecular weight polymers. Imines with a donor substituent on N, such as N‐arylmethyleneimines, polymerized by cationic or anionic mechanism. 1‐ and 2‐Aza‐1,3‐butadienes were also rather unstable and polymerized to oligomers. The symmetrically substituted 2,3‐diaza‐1,3‐butadienes could be purified and polymerized successfully using anionic initiators, resulting in both 1,4‐ and 1,2‐structures in the polymer backbone, depending on the substituents. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Anionic synthesis and detection of fluorescence‐labeled polymers with a terminal anhydride group

To monitor polymer–polymer coupling reactions between two different monofunctional polymers in dilute polymer blends, fluorescence‐labeled anhydride‐functional polystyrene (PS) and poly(methyl methacrylate) (PMMA) were prepared by conventional anionic polymerization. Sequential trapping of lithiopolystyrene by 1‐(2‐anthryl)‐1‐phenylethylene (APE) and then di‐t‐butyl maleate (4) provided, after pyrolysis, anhydride‐functional fluorescent PS. Fluorescent PMMA anhydride (8) was synthesized with sec‐butyllithium/APE as an initiator for the anionic polymerization of methyl methacrylate, trapping by 4, and pyrolysis. These polymers could be reacted with amine‐functional polymers by melt blending, and the reaction progress could be monitored by gel permeation chromatography coupled with fluorescence detection. This technique not only allows monitoring of the coupling reaction with high sensitivity (ca. 100 times more sensitive than refractive index detection) but also permits selective detection because unlabeled polymers are invisible to fluorescence detection. This highly sensitive and selective detection methodology was also used to monitor the coupling reaction of 8 with PS‐NH₂ at a thin‐film interface, which was otherwise difficult to detect by conventional methods. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2177–2185, 2000     

Synthesis and structure of an optically active π‐stacked poly(dibenzofulvene) bearing chiral terminal group

Dibenzofulvene (DBF) affords a polymer having π‐stacked conformation by anionic, cationic, and free‐radical polymerization. In this study, DBF was polymerized anionically using potassium menthoxide as initiator to obtain optically active poly(DBF) having a chiral menthoxy group as a terminal group. The obtained polymer indicated circular dichroism (CD) absorption bands in the absorption wavelength range of fluorenyl group, indicating that chiral conformation was induced to the stacked main chain by the influence of the terminal group. The CD intensity was reversibly affected by temperature of measurement; hence, the chiral conformation may be rather dynamic. The effect of the terminal group was found to decrease as the chain length increased. Theoretical CD calculation indicated that the obtained polymer has a left‐handed helical conformation and that the dihedral angle between neighboring monomeric units might be about 10–20°. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 239–246, 2009     

Asymmetric polymerization of N‐substituted maleimides with chiral oxazolidine–organolithium

Asymmetric anionic homopolymerizations of achiral N‐substituted maleimides (RMI) were performed with lithium 4‐alkyl‐2,2‐dialkyloxazolidinylamide. All obtained polymers were optically active, exhibiting opposite optical rotation to that of a corresponding oxazolidinyl group at the terminal of the main chain. This suggests that opposite optical rotation to the corresponding chiral oxazolidine was induced to the polymer main chain. In the polymerization using a fluorenyllithium (FlLi)–oxazolidine complex, the obtained polymer with a fluorenyl group at the polymer end showed a negative specific rotation. This also suggests that asymmetric induction took place in the polymer main chain. The asymmetric induction was supported by the circular dichroism (CD) and GPC analysis with polarimetric detector. Optical activity of the polymer was attributed to different contents of (S,S) and (R,R) structures formed from threo‐diisotactic additions, as supported by the ¹³C‐NMR spectra of the polymers and the model compounds. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 473–482, 1999     

Synthesis and asymmetric polymerization of (S)‐N‐maleoyl‐L‐leucine propargyl ester

A kind of N‐substituted maleimide (RMI), chiral (S)‐N‐maleoyl‐L ‐leucine propargyl ester ((S)‐PLMI) with a specific rotation of [α]₄₃₅ = ?27.5° was successfully synthesized from maleic anhydride, L ‐leucine, and propargyl alcohol. (S)‐PLMI was polymerized by three polymerization methods to obtain the corresponding optically active polymers. Asymmetric anionic, radical, and transition‐metal‐catalyzed polymerizations were carried out using organometal/chiral ligands, 2,2′‐azobisisobutyronitrile (AIBN) and (bicyclo [2,2,1]hepta‐2,5‐diene) chloro rhodium (I) dimer ([Rh(nbd) Cl]₂), respectively. Poly((S)‐PLMI) obtained by [Rh(nbd)Cl]₂ in DMF showed the highest specific rotation of ?280.6°. Chiroptical properties and structures of the polymers obtained were investigated by GPC, CD, IR, and NMR measurements. Two types of poly((S)‐PLMI)‐bonded‐silica gels as the chiral stationary phase (CSP) were prepared for high‐performance liquid chromatography (HPLC). Their optical resolution abilities were also elucidated. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3722–3738, 2007     

Asymmetric anionic polymerizations of 7‐cyano‐7‐alkoxycarbonyl‐1,4‐benzoquinone methides

Asymmetric anionic polymerizations of 7‐cyano‐7‐alkoxycarbonyl‐1,4‐benzoquinone methides ( 1 ) with various alkoxy groups were performed using chiral initiators such as lithium isopropylphenoxide (ⁱPrPhOLi)/(S)‐(–)‐2,2′‐isopropylidene‐bis(4‐phenyl‐2‐oxazoline) ((–)‐PhBox) and lithium isopropylphenoxide (ⁱPrPhOLi)/(–)‐sparteine ((–)‐Sp) to investigate the effect of the alkoxy groups of alkoxycarbonyl substituent in the monomers 1 and chiral ligands of chiral initiators on the control of chiral center in the formation of polymers. Molar optical rotation values of the polymers were significantly dependent upon alkoxy groups, and the polymers with higher molar optical rotation were obtained in monomers with primary alkoxy groups. The asymmetric anionic oligomerizations of the quinone methides having methoxy( 1a ), ethoxy( 1b ), and n‐propoxy( 1c ) groups with chiral initiators were carried out. Both 1‐mers and 2‐mers were isolated and their optical resolutions were performed to determine the extent of stereocontrol. High stereoselectivity was observed at the propagation reaction, but not at the initiation reaction. The effect of the counterion on the control of chiral center in the formation of the polymer was investigated in the asymmetric anionic polymerizations of 1b with ⁱPrPhOM(M = Li, Na, K)/(–)‐Sp and ⁱPrPhOM(M = Li, Na, K)/(–)‐PhBox initiators and discussed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Chiral polymers for resolution of enantiomers

In 1979, the formation of one‐handed helical poly(triphenylmethyl methacrylate) (PTrMA) was found through the helix‐sense‐selective polymerization of methacrylate using chiral anionic initiators, and the existence of a stable helical polymer without chiral side chains was proved. The chiral polymer exhibited unexpected high chiral recognition of various racemic compounds when used as the chiral packing material (CPM) for HPLC, which was commercialized in 1982 as the first chiral column based on an optically active polymer. This success encouraged us to develop further useful commercial chiral packing materials (CPMs) based on polysaccharides, cellulose, and amylose. By using these polysaccharide‐based CPMs, particularly phenylcarbamate derivatives, nearly 90% of chiral compounds can be resolved not only analytically but also preparatively, and several chiral drugs have been produced using the CPMs. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1731–1739, 2009     

Synthesis and characterization of poly(ethylene oxide‐co‐ethylene carbonate) macromonomers and their use in the preparation of crosslinked polymer electrolytes

Methacrylate‐functionalized poly(ethylene oxide‐co‐ethylene carbonate) macromonomers were prepared in two steps by the anionic ring‐opening polymerization of ethylene carbonate at 180 °C, with potassium methoxide as the initiator, followed by the reaction of the terminal hydroxyl groups of the polymers with methacryloyl chloride. The molecular weight of the polymer went through a maximum after approximately 45 min of polymerization, and the content of ethylene carbonate units in the polymer decreased with the reaction time. A polymer having a number‐average molecular weight of 2650 g mol^?1 and an ethylene carbonate content of 28 mol % was selected and used to prepare a macromonomer, which was subsequently polymerized by UV irradiation in the presence of different concentrations of lithium bis(trifluoromethanesulfonyl)imide salt. The resulting self‐supportive crosslinked polymer electrolyte membranes reached ionic conductivities of 6.3 × 10^?6 S cm^?1 at 20 °C. The coordination of the lithium ions by both the ether and carbonate oxygens in the polymer structure was indicated by Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2195–2205, 2006     

Photoinitiated cationic polymerization of epoxy alcohol monomers

A series of epoxy alcohols were prepared by simple, straightforward methods. These compounds were very reactive monomers that polymerized rapidly on UV irradiation in the presence of cationic photoinitiators. The kinetics of the cationic photopolymerization of these monomers were studied with diaryliodonium salt photoinitiators and real‐time IR spectroscopy. The rate of epoxide ring‐opening polymerization was enhanced markedly by the presence of the hydroxy group. Using model compounds, the monomers were shown to polymerize via an activated monomer mechanism. Simple epoxy alcohols polymerized to give polymers with a hyperbranched structure. The novel monomers also were observed to accelerate the rate of the photopolymerization of mono‐ and multifunctional epoxides. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 389–401, 2000     

Kinetics,polymer molecular weights,and microstructure in zirconocene‐catalyzed 1‐hexene polymerization

1‐Hexene was polymerized by rac‐(dimethylsilyl)bis(4,5,6,7‐tetrahydro‐1‐indenyl)zirconium dichloride catalyst and methylaluminoxane cocatalyst over the temperature range 0–100 °C. The polymerization rate, polymer molecular weight, and polymer microstructure (stereospecificity and regiospecificity) were studied as a function of the temperature and the concentrations of monomer, catalyst, and cocatalyst. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3802–3811, 2000     

Synthesis of well‐defined comb‐like graft (co)polymers by nucleophilic substitution reaction between living polymers and polyhalohydrocarbon

A series of graft (co)polymers were synthesized by nucleophilic substitution reaction between iodinated 1,2‐polybutadiene (PB‐I, backbone) and living polymer lithium (side chains). The coupling reaction between PB‐I and living polymers can finish within minutes at room temperature, and high conversion (up to 92%) could be obtained by effectively avoiding side reaction of dimerization when living polymers were capped with 1,1‐diphenylethylene. By virtue of living anionic polymerization, backbone length, side chain length, and side chain composition, as well as graft density, were well controlled. Tunable molecular weight of graft (co)polymers with narrow molecular weight distribution can be obtained by changing either the lengths of side chain and backbone, or the graft density. Graft copolymers could also be synthesized with side chains of multicomponent polymers, such as block polymer (polystyrene‐b‐polybutadiene) and even mixed polymers (polystyrene and polybutadiene) as hetero chains. Thus, based on living anionic polymerization, this work provides a facile way for modular synthesis of graft (co)polymers via nucleophilic substitution reaction between living polymers and polyhalohydrocarbon (PB‐I). © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Anionic polymerization of o‐substituted styrene derivatives: Control of reactivity and stereochemistry by aminomethyl group

Ortho‐substituted styrenes, such as 2‐(N,N‐dimethylaminomethyl)styrene ( 1 ), 2‐(1‐pyrrolidinylmethyl)styrene ( 2 ), and 2‐[(S)‐2‐(1‐pyrrolidinylmethyl)‐1‐pyrrolidinylmethyl]styrene ( 3 ), were synthesized, and the effects of the ortho‐substituents on the polymerizability and stereoregularity of the obtained polymers using the anionic method were examined. The bulkiness and coordination of the ortho‐substituted amino groups to the counter cation significantly affected the polymerizability and stereochemistry of the obtained polymers. The anionic and radical polymerizations of 2 with a less hindered ortho‐substituent afforded polymers in good yields, whereas those of 1 and 3 resulted in lower yields. The anionic polymerization of 3 bearing an optically active diamine derivative at the ortho‐position with n‐butyllithium in toluene at 0 °C gave a polymer with a high stereoregularity and stable regular conformation based on the stereoregular backbone structure. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4088–4094, 2000     

Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization

Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]_D = +61.0°, polymer [α]_D = ?3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010     

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     

Synthesis of nylon‐6 triblock copolymers with bifunctional polymeric activators

ABA‐type copolymers were synthesized by the anionic polymerization of hexanelactam with the sodium salt of hexanelactam as an initiator and amino‐terminated polytetrahydrofuran telechelic functionalized with diisocyanates. Two types of diisocyanates, hexamethylene diisocyanate (1,6‐diisocyanatohexane) and isophorone diisocyanate (IF; 5‐isocyanato‐1‐isocyanatomethyl‐1,3,3‐trimethylcyclohexane), were used as precursors for polymeric activators (PACs). IF was used for the first time. It was proven that the PACs were incorporated as soft, flexible midblocks in the chains of hard nylon‐6 segments. The polymers were isolated and characterized with various spectroscopic techniques. The effects of the central PAC block (according to the type, molecular weight, and content) and the polymerization conditions on the kinetics, activation energies, molecular weights, and structures of the triblock copolymers were investigated. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4154–4164, 2000     

Synthesis and polymerization studies of formaldehyde oxime and its derivatives

Formaldehyde oxime and three O‐alkyl derivatives were examined as potential imine monomers. Formaldehyde oxime spontaneously polymerized below 60 °C and did not polymerize above 60 °C (ceiling temperature), even in the presence of free‐radical or cationic initiators. The O‐benzoyl derivative was isolated as the cyclic trimer but could not be converted into the monomeric form. Formaldehyde O‐benzyloxime was synthesized and isolated. Attempted homopolymerizations in the presence of free‐radical initiators only led to oligomers, whereas with cationic initiators only cyclic trimer was obtained. Copolymerizations with appropriate vinyl monomers and free‐radical and anionic initiators yielded only low molecular weight polymers. Cationic copolymerizations gave higher molecular weights and polymer yields, but the polymers containing appreciable amounts of imine function had very low molecular weights. We conclude that the polymerizability of imines is extremely sensitive to the substitution pattern: imines with only a substituent on nitrogen are unstable and readily polymerize, whereas imines with more substituents generally do not polymerize. Electron‐withdrawing substituents are more favorable to polymerizability. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1866–1872, 2000     

Asymmetric polymerization of the mixture of TrMA and MMA initiated by chiral complexes

A mixture of triphenylmethyl methacrylate (TrMA) and methyl methacrylate (MMA) was polymerized with chiral anionic initiator, such as fluorenyl lithium(−)-sparteine [FlLi-(−)-Sp] and fluorenyl lithium-(+)-2S,3S-dimethoxy-1,4-bis(dimethylamino)butane [FlLi-(+)-DDB] in toluene at −78°C. The results show that after the stable helix formed, when FlLi-(+)-DDB was used as the initiator, TrMA and MMA could be copolymerized, whereas when FlLi-(−)-Sp was used, the two monomers tended to be selectively polymerized into two polymers. This phenomenon has been explained by the existence of helix-selective polymerization. © John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1925–1931, 1997     

Water‐soluble polymers from acid‐functionalized norbornenes

Unprotected exo,exo‐5‐norbornene‐2,3‐dicarboxylic acid and exo,exo‐7‐oxa‐5‐norbornene‐2,3‐dicarboxylic acid were polymerized via ring‐opening metathesis polymerization. This reaction yielded polymers with molecular weights (M_n from GPC) ranging from 31 to 242 kg/mol and polydispersity indices between 1.05 and 1.12, using Grubbs' third generation catalyst. The water solubility as a function of pH value of the polymers was investigated by dynamic light scattering (DLS). DLS and acid‐base titration revealed that the oxanorbornene polymer was water soluble over a wider pH range than its norbornene analog. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1266–1273, 2009     

Emulsion procedures for thermally reversible covalent crosslinking of polymers

Quaternization and dequaternization of tertiary amine compounds were employed to obtain thermally reversible ionene networks from aqueous colloidal polymer dispersions prepared via emulsion polymerization. Chlorine‐functionalized polymers prepared via the emulsion copolymerization of styrene (St), butylacrylate (BA), or both with chloromethylstyrene, and amino‐functionalized polymers prepared via the emulsion copolymerization of St, BA, or both with 2‐(dimethylamino)ethylacrylate or 4‐vinylpyridine, were reacted without polymer separation, with a ditertiaryamine crosslinker and a dihalide crosslinker, respectively, to obtain crosslinked polymers. Crosslinked polymers were also obtained via the reaction of a chlorine‐functionalized polymer dispersion with an amino‐functionalized polymer dispersion or via the drying of the polymer blend prepared from the two kinds of dispersions. Reactive solubility experiments, flowability investigations (by thermocompression at ca. 215 °C), IR, and ¹H NMR analyses of the obtained crosslinked polymers indicated that the generated ionene bridges dequaternized on heating and requaternized on cooling. In comparison with solution crosslinking, no organic solvent was employed, and simple procedures were required for the preparation of the thermally reversible covalent crosslinked polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4373–4384, 2000     

Development of hydrogenated ring‐opening metathesis polymers

New hydrogenated ring‐opening metathesis polymers with excellent thermal and optical properties were developed. These polymers were prepared by the ring‐opening metathesis polymerization of ester‐substituted tetracyclododecene monomers followed by the hydrogenation of the main‐chain double bond. The degree of hydrogenation was an important factor for the thermal stability of the polymers, and as complete hydrogenation as possible was necessary to obtain a thermally stable polymer. The completely hydrogenated ring‐opening polymer derived from 8‐methyl‐8‐methoxycarbonyl‐substituted monomer has a glass‐transition temperature of 171 °C and a 5% weight‐loss temperature of 446 °C. This polymer has excellent thermal and optical properties because of its bulky and unsymmetrical polycyclic structure in the main chain and is an alternative to glass or other transparent polymers such as poly(methyl methacrylate) and polycarbonate resin. This polymer has also been used in a wide variety of applications, such as optical lenses, optical disks, optical films, and optical fiber. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4661–4668, 2000