Synthesis of well‐defined azide‐terminated poly(vinyl alcohol) and their subsequent modification via click chemistry

A new azide‐functionalized xanthate, S‐(4‐azidomethylbenzyl) O‐(2‐methoxyethyl) xanthate, was synthesized and used to mediate the reversible addition fragmentation chain transfer polymerization of vinyl acetate. The polymerization was demonstrated to be controlled, and well‐defined PVAc with α‐azide, ω‐xanthate groups were obtained, the xanthate groups of which were further removed by radical‐induced reduction with lauroyl peroxide in the presence of excess 2‐propanol. Hydrolysis of α‐azide‐terminated PVAc (N₃‐PVAc) led to the formation of the corresponding α‐azide‐terminated PVA (N₃‐PVA). Finally, end‐modification of N₃‐PVA by click chemistry with alkyne‐end‐capped poly(caprolactone) (A‐PCL), alkynyl‐mannose, and alkynyl‐pyrene was carried out to obtain a new block copolymer PCL‐b‐PVA, and two PVA with mannose or pyrene as the end functional groups. The polymers were characterized by gel permeation chromatography, ¹H NMR spectroscopy, and FTIR. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4494–4504, 2009     

3‐miktoarm star terpolymers using triple click reactions: Diels–Alder,copper‐catalyzed azide‐alkyne cycloaddition,and nitroxide radical coupling reactions

Well‐defined linear furan‐protected maleimide‐terminated poly(ethylene glycol) (PEG‐MI), tetramethylpiperidine‐1‐oxyl‐terminated poly(ε‐caprolactone) (PCL‐TEMPO), and azide‐terminated polystyrene (PS‐N₃) or ‐poly(N‐butyl oxanorbornene imide) (PONB‐N₃) were ligated to an orthogonally functionalized core ( 1 ) in a two‐step reaction mode through triple click reactions. In a first step, Diels–Alder click reaction of PEG‐MI with 1 was performed in toluene at 110 °C for 24 h to afford α‐alkyne‐α‐bromide‐terminated PEG (PEG‐alkyne/Br). As a second step, this precursor was subsequently ligated with the PCL‐TEMPO and PS‐N₃ or PONB‐N₃ in N,N‐dimethylformamide at room temperature for 12 h catalyzed by Cu(0)/Cu(I) through copper‐catalyzed azide‐alkyne cycloaddition and nitroxide radical coupling click reactions, yield resulting ABC miktoarm star polymers in a one‐pot mode. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Aromatic poly(1,3,4‐oxadiazole)s and poly(amide‐1,3,4‐oxadiazole)s containing ether sulfone linkages

Polyhydrazides and poly(amide‐hydrazide)s were prepared from two ether‐sulfone‐dicarboxylic acids, 4,4′‐[sulfonylbis(1,4‐phenylene)dioxy]dibenzoic acid and 4,4′‐[sulfonylbis(2,6‐dimethyl‐1,4‐phenylene)dioxy]dibenzoic acid, or their diacyl chlorides with terephthalic dihydrazide, isophthalic dihydrazide, and p‐aminobenzhydrazide via a phosphorylation reaction or a low‐temperature solution polycondensation. All the hydrazide polymers were found to be amorphous according to X‐ray diffraction analysis. They were readily soluble in polar organic solvents such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide and could afford colorless, flexible, and tough films with good mechanical strengths via solvent casting. These hydrazide polymers exhibited glass‐transition temperatures of 149–207 °C and could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the solid state at elevated temperatures. Although the oxadiazole polymers showed a significantly decreased solubility with respect to their hydrazide prepolymers, some oxadiazole polymers were still organosoluble. The thermally converted oxadiazole polymers had glass‐transition temperatures of 217–255 °C and softening temperatures of 215–268 °C and did not show significant weight loss before 400 °C in nitrogen or air. For a comparative study, related sulfonyl polymers without the ether groups were also synthesized from 4,4′‐sulfonyldibenzoic acid and the hydrazide monomers by the same synthetic routes. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2271–2286, 2001     

Synthesis,characterization, and electroluminescence of PPV copolymers containing electron and hole‐transporting units

Three series of poly(phenylene vinylene) (PPV) derivatives containing hole‐transporting triphenylamine derivatives [N‐(4‐octoxylphenyl)diphenylamine, N,N′‐di(4‐octyloxylphenyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine, and N,N′‐di(4‐octoxylphenyl)‐N,N′‐diphenylbenzidine] (donor) and electron‐transporting oxadiazole unit (2,5‐diphenyl‐1,3,4‐oxadiazole) (acceptor) in the main chain were synthesized by improved Wittig copolymerization. The resulting donor–acceptor (D‐A) polymers are readily soluble in common organic solvents, such as chloroform, dichloroethane, THF, and toluene. The polymers containing oxadiazole group exhibit good thermal stability with 5% weight loss above 400 °C. The intramolecular charge‐transfer was observed in these D‐A polymers. In comparison with corresponding polymers without oxadiazole unit, the single‐layer devices based on the D‐A polymers showed much improved electroluminescent properties, because of the balanced charge injection and transport. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1566–1576, 2008     

Head‐to‐head polymers

Head‐to‐head (H–H) linkages were observed in addition and condensation polymers. Pure H–H polymers of polyolefins, poly(vinyl halides), and polyacrylates were prepared, and the fundamental polymer properties were determined. They included mechanical, spectral, thermal, and degradation behaviors. These properties were compared with those of the traditional head‐to‐tail polymers. Blends of H–H polymers were also studied. The thermal and thermal‐degradation behaviors of the blends were also investigated. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4013–4022, 2000     

Poly(arylether amides) and poly(aryletherketone amides) via aromatic nucleophilic substitution reactions of self‐polymerizable AB and AB2 monomers

Two new extended self‐polymerizable AB monomers, N‐(4‐fluorobenzoyl)‐4‐amino‐4′‐hydroxydiphenylether and N‐(4‐fluorobenzoyl)‐4‐amino‐4′‐hydroxybiphenyl, were prepared. The monomers were homopolymerized and copolymerized to high‐molecular‐weight, linear poly(arylether amides) in N‐methylpyrrolidone (NMP)/toluene in the presence of potassium carbonate at elevated temperature. The polymers retained NMP up to 200 °C. Samples containing small amounts of the solvent (5–10 wt %) were soluble in polar aprotic solvents. However, after complete removal of the NMP, the polymers were only soluble in strong acids such as sulfuric acid and methanesulfonic acid (MSA). The polymers, which had intrinsic viscosities of 0.57–1.49 dL/g (30.1 ± 0.1 °C in MSA), were semicrystalline with melting temperatures above 400 °C. Two new self‐polymerizable AB₂ amide monomers, N,N′‐bis(4‐fluorobenzoyl)‐3,4‐diamino‐4′‐hydroxydiphenylether and N,N′‐bis(4‐fluorobenzoyl)‐3,5‐diamino‐4′‐hydroxybenzophenone, were also prepared and polymerized to give a hyperbranched poly(arylether amide) and a hyperbranched poly(aryletherketone) amide. The arylfluoride‐terminated, amorphous polymers had intrinsic viscosities of 0.34 and 0.24 dL/g (30.0 ± 0.1 °C in m‐cresol), glass‐transition temperatures of 210–269 °C, and were soluble in a wide variety of organic solvents. Matrix‐assisted laser desorption/ionization time‐of‐flight analysis indicated that the components of the low‐molecular‐weight fractions contained cyclic structures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2374–2389, 2003     

Diblock copolymers,micelles, and shell‐crosslinked nanoparticles containing poly(4‐fluorostyrene): Tools for detailed analyses of nanostructured materials

Amphiphilic core–shell nanostructures containing ¹⁹F stable isotopic labels located regioselectively within the core domain were prepared by a combination of atom transfer radical polymerization (ATRP), supramolecular assembly, and condensation‐based crosslinking. Homopolymers and diblock copolymers containing 4‐fluorostyrene and methyl acrylate were prepared by ATRP, hydrolyzed, assembled into micelles, and converted into shell‐crosslinked nanoparticles (SCKs) by covalent stabilization of the acrylic acid residues in the shell. The ATRP‐based polymerizations, producing the homopolymers and diblock copolymers, were initiated by (1‐bromoethyl)benzene in the presence of CuBr metal and employed N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the coordinating ligand for controlled polymerizations at 75–90 °C for 1–3 h. Number‐average molecular weights ranged from 2000 to 60,000 Da, and molecular weight distributions, generally less than 1.1 and 1.2, were achieved for the homopolymers and diblock copolymers, respectively. Methyl acrylate conversions as high as 70% were possible, without observable chain–chain coupling reactions or molecular weight distribution broadening, when bromoalkyl‐terminated poly(4‐fluorostyrene) was used as the macroinitiator. Poly(4‐fluorostyrene), incorporated as the second segment in the diblock copolymer synthesis, was initiated from a bromoalkyl‐terminated poly(methyl acrylate) macroinitiator. After hydrolysis of the poly(methyl acrylate) block segments, micelles were formed from the resulting amphiphilic block copolymers in aqueous solutions and were then stabilized by covalent intramicellar crosslinking throughout the poly(acrylic acid) shells to yield SCKs. The SCK nanostructures on solid substrates were visualized by atomic force microscopy and transmission electron microscopy. Dynamic light scattering was used to probe the effects of crosslinking on the resulting hydrodynamic diameters of nanoparticles in aqueous and buffered solutions. The presence of fluorine atoms in the diblock copolymers and resulting SCK nanostructures allowed for characterization by ¹⁹F NMR in addition to ¹H NMR, ¹³C NMR, and IR spectroscopy. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4152–4166, 2001     

Synthesis and characterization of 6‐ and 12‐arm star polymers by nitroxide‐mediated radical polymerization of St and MA from dendritic TIPNO‐based hexafunctional and dodecafunctional macroinitiators

Dendritic multifunctional macroinitiators having six and 12 TIPNO‐based alkoxyamines, TIPNO‐6 and TIPNO‐12 , were synthesized and used in the living radical polymerization of styrene (St), methyl acrylate (MA), N,N‐dimethylacrylamide (DMAAm), and isoprene (IP). The polymerizations of St initiated with TIPNO‐6 gave 6‐arm star polymers with narrow polydispersities of 1.14–1.18. In the polymerizations of MA initiated with TIPNO‐6 and TIPNO‐12 , the influences of added TIPNO on the polydispersity indexes (PDIs) of the resulting star polymers were first investigated, and this led to the successful formation of poly(MA) star polymers with narrow polydispersities (1.10–1.18). Moreover, the polymerizations of DMAAm and IP from TIPNO‐6 in the presence or absence of TIPNO were briefly investigated. The benzyl ether bonds of the poly(St) and poly(MA) star polymers were cleaved by treating with Me₃SiI or Pd/C, and the resulting arm's parts were analyzed with SEC. The PDIs of the resulting arm parts were low (1.19–1.23), and the M_ns agreed with the M_n,theor, indicating that the poly(St) and poly(MA) star polymers had well‐controlled arms. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4364–4376, 2007     

Linear tetrablock quaterpolymers via triple click reactions,azide‐alkyne,diels–alder,and nitroxide radical coupling in a one‐pot fashion

Azide‐alkyne and Diels–Alder click reactions together with a click‐like nitroxide radical coupling reaction were used in a one‐pot fashion to generate tetrablock quaterpolymer. The various living polymerization generated linear polymers with orthogonal end‐functionalities, maleimide‐terminated poly(ethylene glycol) (PEG‐MI), anthracene‐ and azide‐terminated polystyrene, alkyne‐ and bromide‐terminated poly(tert‐butyl acrylate) or alkyne‐poly(n‐butyl acrylate), and tetramethylpiperidine‐1‐oxyl (TEMPO)‐terminated poly(ε‐caprolactone) (PCL‐TEMPO) were clicked together in a one‐pot fashion to generate PEG‐b‐PS‐b‐PtBA‐b‐PCL or PEG‐b‐PS‐b‐PnBA‐b‐PCL quaterpolymer using Cu(0), CuBr, and N,N,N′,N″,N″‐pentamethyldiethylenetriamine as catalyst in dimethyl formamide at 80 °C for 36 h. Linear precursors and target quaterpolymers were analyzed via ¹H NMR and gel permeation chromatography. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Durable and refreshable polymeric N‐halamine biocides containing 3‐(4′‐vinylbenzyl)‐5,5‐dimethylhydantoin

A novel vinyl‐hydantoin monomer, 3‐(4′‐vinylbenzyl)‐5,5‐dimethylhydantoin, was synthesized in a good yield and was fully characterized with Fourier transform infrared (FTIR) and ¹H NMR spectra. Its homopolymer and copolymers with several common acrylic and vinyl monomers, such as vinyl acetate, acrylonitrile, and methyl methacrylate, were readily prepared under mild conditions. The polymers were characterized with FTIR and ¹H NMR, and their thermal properties were analyzed with differential scanning calorimetry studies. The halogenated products of the corresponding copolymers exhibited potent antibacterial properties against Escherichia coli, and the antibacterial properties were durable and regenerable. The structure–property relationships of the polymers were further discussed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3348–3355, 2001     

Well‐defined PE‐b‐PDMS diblock copolymers via the combination of thiol‐ene click and esterification reactions: Facile synthesis and compatibilization for HDPE/silicone oil blends

Well‐defined diblock copolymers of linear polyethylene (PE) and poly(dimethylsiloxane) (PDMS) have been synthesized through a facile route combining the thiol‐ene click chemistry of vinyl‐terminated polyethylene (PE‐ene) and the sequential esterification reaction. The resulting diblock copolymers are characterized by ¹H NMR, FT‐IR, DSC, TGA, and TEM. In addition, the PE‐b‐PDMS diblock copolymers have been evaluated as compatibilizers in the blends of high‐density polyethylene (HDPE) and silicone oil. The morphological analysis and mechanical properties demonstrate that the compatibilized blends with low loading concentration of PE‐b‐PDMS display significant improvements in modulus of elasticity and elongation at break as compared to the uncompatibilized binary blends. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3205–3212     

Synthesis and miscibility studies of [60]fullerenated poly(2‐hydroxyethyl methacrylate)

[60]Fullerenated poly(2‐hydroxyethyl methacrylate)s containing 0.6–3.0 wt % C₆₀ were synthesized. These polymers are soluble in methanol and N,N‐dimethylformamide (DMF). [60]Fullerenated poly(2‐hydroxyethyl methacrylate)s with higher C₆₀ contents are only sparingly soluble in DMF and virtually insoluble in other organic solvents. A loading of 1.2 wt % C₆₀ in poly(2‐hydroxyethyl methacrylate) does not greatly affect its miscibility with poly(N‐vinyl‐2‐pyrrolidone), poly(1‐vinylimidazole), and poly(4‐vinylpyridine). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1157–1166, 2002     

Synthesis of hyperbranched poly(ether nitrile)s by one‐step polycondensation of an AB2 monomer

Hyperbranched poly(ether nitrile)s were prepared from a novel AB₂ type monomer, 2‐chloro‐4‐(3,5‐dihydroxyphenoxy)benzonitrile, via nucleophilic aromatic substitution. Soluble and low‐viscous hyperbranched polymers with molecular weights upto 233,600 (M_w) were isolated. According to the ¹H NMR and GPC data, the unique polymerization behavior was observed, which implies that the weight average molecular weight increased after the number average molecular weight reached plateau region. Model compounds were prepared to characterize the branching structure. Spectroscopic measurements of the model compounds and the resulting polymers, such as ¹H, DEPT ¹³C NMR, and MS, strongly suggest that the ether exchange reaction and cyclization are involved in the propagation reaction. The side reactions would affect the unique polymerization behavior. The resulting polymers showed a good solubility in organic solvents similar to other hyperbranched aromatic polymers. The hydroxy‐terminated polymer was even soluble in basic water. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5835–5844, 2009     

Synthesis and crosslinking of biphenyl and naphthalene liquid‐crystalline polyethers with pendant full‐saturated and vinyl‐terminated aliphatic chains

Two series of vinyl‐terminated, side‐chain liquid‐crystalline polyethers containing 4,4′‐biphenyl and 2,6‐naphthalene moieties as mesogenic cores with several contents of vinyl crosslinkable groups were synthesized by chemically modifying poly(epichlorohydrin) with mixtures of saturated and vinyl‐terminated mesogenic acids. In most cases the degree of modification was over 90%. The polymers were characterized by chlorine analysis, IR and ¹H and ¹³C NMR spectroscopies, viscometry, size exclusion chromatography/multi‐angle laser light scattering, and thermogravimetric analysis. The liquid‐crystal behavior of all the synthesized polymers was examined by differential scanning calorimetry, polarized optical microscopy (POM), and X‐ray diffraction on mechanically oriented samples. The crosslinking of most polymers was done by peroxide‐type initiators, which generally led to liquid‐crystal elastomers. The mesophase organization was maintained on the crosslinked materials, as confirmed by POM and X‐ray diffraction. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3384–3399, 2003     

Synthesis and characterization of new highly organosoluble poly(etherimide)s derived from 1,1‐bis{4‐[4‐(3,4‐dicarboxyphenoxy)phenyl]‐4‐phenylcyclohexane} dianhydride

A new bulky pendent bis(ether anhydride), 1,1‐bis[4‐(4‐dicarboxyphenoxy)phenyl]‐4‐phenylcyclohexane dianhydride, was prepared in three steps, starting from the nitrodisplacement of 1,1‐bis(4‐hydroxyphenyl)‐4‐phenylcyclohexane with 4‐nitrophthalonitrile to form bis(ether dinitrile), followed by alkaline hydrolysis of the bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). A series of new poly(ether imide)s were prepared from the bis(ether anhydride) with various diamines by a conventional two‐stage synthesis including polyaddition and subsequent chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities of 0.50–0.73 dL g^?1. The gel permeation chromatography measurements revealed that the polymers had number‐average and weight‐average molecular weights of up to 57,000 and 130,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility in comparison with the other polyimides derived from adamantane, norbornane, cyclododecane, and methanohexahydroindane and were readily dissolved in various solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and even chloroform. These polymers had glass‐transition temperatures of 226–255 °C. Most of the polymers could be dissolved in chloroform in as high as a 30 wt % concentration. Thermogravimetric analysis showed that all polymers were stable up to 450 °C, with 10% weight losses recorded from 458 to 497 °C in nitrogen. These transparent, tough, and flexible polymer films could be obtained by solution casting from DMAc solutions. These polymer films had tensile strengths of 79–103 MPa and tensile moduli of 1.5–2.1 GPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2066–2074, 2002     

Ring‐opening metathesis polymerization as a route to controlled copolymers of ethylene and polar monomers: Synthesis of ethylene–vinyl chloride‐like copolymers

A series of ethylene–vinyl chloride‐like copolymers were prepared by ring‐opening metathesis polymerization (ROMP). The route to these materials included the bulk polymerization of 5‐chlorocyclooctene and 5,6‐dichlorocyclooctene with the first‐generation Grubbs' catalyst, followed by diimide hydrogenation of the resulting unsaturated polymers. In addition, the amount of chlorine in these materials was varied by the copolymerization of 5‐chlorocyclooctene with cyclooctene. These materials were fully characterized by NMR (¹H and ¹³C), gel permeation chromatography, and Fourier transform infrared spectroscopy. Finally, hydroboration was carried out on the ROMP product of 5‐chlorocyclooctene to yield a polymer, which was effectively a vinyl alcohol–vinyl chloride–ethylene terpolymer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2107–2116, 2003     

N‐alkoxy pyridinium ion terminated polystyrenes: A facile route to photoinduced block copolymerization

Photoactive N‐alkoxy 4‐phenyl pyridinium and N‐alkoxy isoquinolinium ion terminated polystyrenes with hexafluoroantimonate counter anion were prepared and characterized. For this purpose, mono‐ and dibrominated polystyrenes were prepared by atom transfer radical polymerization (ATRP). The reaction of these polymers with silver hexafluoroantimonate in the presence of 4‐phenylpyridine N‐oxide and isoquinoline N‐oxide in dichloromethane produced desired polymeric salts with the corresponding functionalities. Irradiation of these photoactive polystyrenes produced alkoxy radicals at chain ends capable of initiating free radical polymerization of methyl methacrylate (MMA). This way, depending on the number of functionality, AB or ABA type block copolymers were formed which were characterized with the aid of gel permeation chromatography and ¹H NMR spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 423–428, 2007.     

Direct copolymerization of sulfonated poly(phthalazinone arylene ether)s for proton‐exchange‐membrane materials

Sulfonated poly(phthalazinone ether ketone) (SPPEK) copolymers and sulfonated poly(phthalazinone ether sulfone) (SPPES) copolymers containing pendant sodium sulfonate groups were prepared by direct copolymerization. The reaction of disodium 3,3′‐disulfonate‐4,4′‐difluorobenzophenone (SDFB‐Na), 4,4′‐difluorobenzophenone (DFB), and 4‐(4‐hydroxyphenyl)‐1(2H)‐phthalazinone (DHPZ) at 170 °C in N‐methyl‐2‐pyrrolidione containing anhydrous potassium carbonate gave SPPEKs. SPPESs were similarly obtained with 3,3′‐disulfonate‐4,4′‐difluorophenyl sulfone, 4‐fluorophenyl sulfone (DFS), and DHPZ as monomers. The sulfonic acid groups, being on deactivated positions of the polymer backbone, were expected to be hydrolytically more stable than postsulfonated polymers. Fourier transform infrared and ¹H NMR were used to characterize the structures and degrees of sulfonation of the sulfonated polymers. Membrane films of SPPEKs with SDFB‐Na/DFB molar feed ratios of up to 60/40 and SPPESs with sulfonated 4‐fluorophenyl sulfone/DFS molar feed ratios of up to 50/50 were cast from N,N‐dimethylacetamide polymer solutions. Membrane films in acid form were then obtained by the treatment of the sodium‐form membrane films in 2 N sulfuric acid at room temperature. An increase in the number of sulfonate groups in the copolymers resulted in an increased glass‐transition temperature and enhanced membrane hydrophilicity. The sodium‐form copolymers were thermally more stable than their acid forms. The proton conductivities of the acid‐form copolymers with sulfonated monomer/unsulfonated monomer molar feed ratios of 0.5 and 0.6 were higher than 10^?2 S/cm and increased with temperature; they were less temperature‐dependent than those of the postsulfonated products. SPPESH‐50 showed higher conductivity than the corresponding postsulfonated poly(phthalazinone ether sulfone). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2731–2742, 2003     

Synthesis and characterization of new highly organosoluble poly(ether imide)s based on 3,3′,5,5′‐tetramethyl‐2,2‐bis[4‐(4‐dicarboxyphenoxy)phenyl]propane dianhydride

A new bis(ether anhydride), 3,3′,5,5′‐tetramethyl‐2,2‐bis[4‐(4‐dicarboxyphenoxy)phenyl]propane dianhydride ( 3 ), was prepared in three steps: the nitro displacement of 4‐nitrophthalonitrile with 2,2‐bis(4‐hydroxy‐3,5‐dimethylphenyl)propane, the alkaline hydrolysis of the intermediate bis(ether dinitrile), and the subsequent dehydration of the resulting bis(ether diacid). A series of new highly soluble poly(ether imide)s with tetramethyl and isopropylidene groups were prepared from the bis(ether anhydride) 3 with various diamines by a conventional two‐stage synthesis including polyaddition and chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities of 0.54–0.73 dL g^?1. Gel permeation chromatography measurements revealed that the polymers had number‐average and weight‐average molecular weights of up to 54,000 and 124,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility and were readily dissolved in various solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and even chloroform. Most of the polymers could be dissolved with chloroform concentrations as high as 30 wt %. These polymers had glass‐transition temperatures of 244–282 °C. Thermogravimetric analysis showed that all polymers were stable, with 10% weight losses recorded above 463 °C in nitrogen. These transparent, tough, and flexible polymer films were obtained through solution casting from N,N‐dimethylacetamide solutions. These polymer films had tensile strengths of 81–102 MPa and tensile moduli of 1.8–2.0 GPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2556–2563, 2002     

Synthesis and properties of oxygen‐, methylene‐, and alkylene‐bridged poly(dithiafulvene)s

Polymerization by cycloaddition between aldothioketene and its alkynethiol tautomer (derived in situ from a diyne) leading to the formation of dithiafulvene unit‐linked polymers has been studied. Two aromatic diynes [bis(4‐ethynyldiphenyl)methane ( 1a ) and 4,4′‐diethynyldiphenyl ether) ( 1b )] were used as starting materials with the aim of obtaining non‐π‐conjugated methylene‐ and oxygen‐bridged aromatic poly(dithiafulvene)s. The poly(dithiafulvene) derived from bis(4‐ethynyldiphenyl)methane can be considered as an interesting precursor to a small band‐gap polymer having alternating aromatic and quinonoid moieties. Further, two aliphatic diynes [1,7‐octadiyne ( 3a ) and 1,9‐decadiyne ( 3b )] were subjected to cycloaddition polymerization to obtain aliphatic poly(dithiafulvene)s containing localized electron‐rich dithiafulvene units. The polymers obtained were characterized by IR, ¹H NMR, gel permeation chromatography, and cyclic voltammetry. The electron‐donating property of the polymers was evident from the charge‐transfer (CT) complex formation with an electron acceptor 7,7,8,8‐teracyanoquinodimethane. The CT complexes were characterized by IR, ¹H NMR, and ultraviolet–visible spectroscopies. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3593–3603, 2001