Synthesis and characterization of a new disubstituted polyacetylene containing indolylazo moieties in side chains

A new disubstituted polyacetylene with indolylazo moieties in its side chains ( 9 ) was synthesized by a post functionalization strategy, which was difficult, or perhaps impossible, to obtain from the direct polymerization of its corresponding monomer. The polymer is soluble in common solvents and thermally stable. The polymer shows good optical transparency with an absorption maximum at 393 nm and a band edge at ～530 nm. Its poled film exhibits a resonant d₃₃ value of 17.9 pm/V and its optical nonlinearity is resistant to thermal decay at up to 147 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5672–5681, 2006     

Synthesis and characterization of an acrylate polymer containing chlorine-1,3-dioxalane groups in side chains

Poly[2-（4-chlorophenyl）-1,3-dioxolan-4-yl]methyl acrylate,poly（CPhDMA）,was synthesized with radical polymerization process using 2,2′-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃.The structure of poly（CPhDMA） was confirmed by means of UV-Vis,FT-IR,¹H-NMR,and ¹³C-NMR spectral techniques.The molecular weight distribution values of the polymer were determined with gel permeation chromatography（GPC）.The number-average molecular weight（M_n）,weight-average molecular weight（M_W） and polydispersity index（PDI） values of poly（CPhDMA） were determined to be 10300,21600 and 2.097,respectively.The thermal degradation kinetics of the polymer was investigated by using TG/DTG-DTA and DSC analyses at different heating rates in dynamic nitrogen atmosphere.The apparent activation energy values obtained by Flynn-Wall-Ozawa and Friedman methods were found to be 91.68 and 85.23 kJ mol^-1,respectively,for thermal decomposition of poly（CPhDMA）.Also,the thermal degradation activation energy value of poly（CPhDMA） was calculated by using the Kissinger method based on the DTG,DTA and DSC data.Then the mechanism function of it was determined by master plots method.Finally,electrical and optical properties of poly（CPhDMA） were determined by four-point probe and UV-Vis techniques,respectively.     

Poly(arylene ether ether nitrile)s containing flexible alkylsulfonated side chains for polymer electrolyte membranes

A series of poly(arylene ether ether nitrile)s with different chain lengths of the alkylsulfonates (SPAEEN‐x: x refers number of the methylene units) are successfully synthesized for fuel cell applications. The polymers produced flexible and transparent membranes by solvent casting. The resulting membranes display a high thermal stability, oxidative stability, and higher proton conductivity than that of Nafion 117 at 80 °C and 95% relative humidity (RH). Furthermore, the SPAEEN‐12 with the longest alkylsulfonated side chain exhibits a higher proton conductivity at 30% RH than that of SPAEEN‐6 despite the lower IEC value, which indicates that the introduction of longer alkylsufonated side chains to the polymer main chain induces an efficient proton conduction by the formation of a well‐developed phase‐separated morphology. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 21–29     

Synthesis and characterization of PEGylated comb-like cationic polymer by polycondensation and ATRP

PEGylated poly(2-(dimethylamino)ethyl methacrylate) with comb-like architecture was synthesized by two-step polymerization. First,poly(oligo(ethylene glycol) malicate)(POEGMA) bearing pendant hydroxyl groups was prepared by direct polycondensation of oligo(ethylene glycol) and malic acid in the presence of scandium triflate as chemoselective catalyst.Then the poly(2- (dimethylamino)ethyl methacrylate) side chains were grafted from the POEGMA backbone by atom transfer radical polymerization (ATRP) after the hydroxyl groups were modified into bromo-ester form,resulting in a PEGylated cationic copolymer with branched architecture.     

Synthesis of dendronized polymer brushes containing metallo‐supramolecular polymer side chains

A new kind of dendronized polymer brush with metallo‐supramolecular polymer side chains was fabricated by a combination of macromonomer and graft‐to approach. The alternating copolymers of maleic anhydride and styryl macromonomers pendant with Fréchet‐type dendrons of three generations were reported previously. In this article, terpyridine groups were introduced along the backbone of the dendronized polymers through the amidolysis of anhydride groups. The terpyridine functionalized PEO linear chains were then incorporated through the complexation of terpyridine and Ru(II) ion. Thus, dendronized polymer brushes with amphiphilic properties were synthesized. AFM analysis showed worm‐like single molecular morphologies of the polymers of three generations, and ¹H NMR analysis indicated that such molecular brushes had an amphiphilic nature in solution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3303–3310, 2007     

Synthesis and characterization of polyyne polymer containing nickel in the main chain

The synthesis of the nickel dialkynyl complex Ni(C?C? C₆H₄? C?CH)₂(PPh₃)₂ and of the corresponding polyyne polymer containing nickel in the main chain ? [Ni(PPh₃)₂? C?C? C₆H₄? C?C? ]_n are described and discussed. A new mixed solvent system DMSO/HNEt₂ and homogeneous step-wise condensation method used for their synthesis are presented for the first time. The Ni-polyyne polymer obtained is dark yellow powder and soluble in THF or CH₂Cl₂. Its M?_w is about 10⁴, and the MWD is less than 2. Both the prepared complex and polymer have been characterized by IR, UV, ¹H-NMR, and DTA. Preliminary results on photoluminesence of nickel polyyne polymers are present. © 1995 John Wiley & Sons, Inc.     

Preparation and characterization of a new polymer electrolyte (PEO:NaClO3) for battery application

A new sodium-ion conducting thin-film polymer electrolyte based on the poly(ethylene oxide) (PEO) system has been prepared by a solution-casting method. Characterization by XRD, IR, and AC conductivity and Wagner's polarization were carried out on these thin-film electrolytes. From the transference number experiment it was found that the charge transport in these electrolytes is mainly due to ions. Conductivity studies show that the conductivity value of the PEO:NaClO₃ complex increases with the increase of salt concentration. An increase in the conductivity and a change in the cell parameters for the electrolyte system were found by the addition of the low molecular weight dimethylformamide or propylene carbonate as plasticizers. The cell parameters of these electrolyte systems were measured from a discharge study of the cell with the application of a load of 100 kΩ at room temperature in the common cell configuration Na|electrolyte|MnO₂. The open circuit voltage ranges from 2.02 V to 2.46 V and the short circuit current ranges from 570 μA to 1030 μA. Electronic Publication     

Fabrication and evaluation of a polymer Li-ion battery with microporous gel electrolyte

This paper introduces an easy method for the fabrication of polymer Li-ion batteries with microporous gel electrolyte (MGE). The MGE is a multiphase electrolyte, which is composed of liquid electrolyte, gel electrolyte, and polymer matrix. The MGE not only has high ionic conductivity and good adhesion to the electrodes at low temperatures, but also retains good mechanical strength at elevated temperatures. Therefore, the MGE batteries are able to operate over a wide temperature range. During battery fabrication, the MGE is formed in situ by introducing liquid electrolyte into a swellable microporous polymer membrane and then heating or cycling the battery. In this work, the chemical compatibility of MGE with metal lithium during 60 °C storage and with LiMn₂O₄ cathode during cycling was studied. In addition, graphite/MGE/LiMn₂O₄ Li-ion batteries were made and evaluated.     

Synthesis and characterization of a novel arylacetylene oligomer containing POSS units in main chains

A novel arylacetylene oligomer containing octamethyl POSS units in main chains was prepared from difluoride octamethyl POSS (diexo-(CH₃)₈Si₈O₁₁F₂) and diethynylbenzene (DEB) by Grignard reaction and characterized by FT-IR, NMR, WAXD, GPC, DSC, and TGA. The curing reaction kinetic of the oligomer was studied by Kissinger and Ozawa methods and the kinetic parameters were obtained. The cured polymer had good thermal and thermal-oxidative properties. TGA analyses demonstrated that the thermal decomposition temperature (T_d5) of the cured polymer in nitrogen and air were 503 and 479 °C, respectively.     

Elastic behavior of comb-like polymer chains

<正>Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths N_b,arm lengths N_a and arm densities m are carried out to study the elastic behavior of comb-like polymer chains.The radius of gyration,the shape factors and bond length in different cases during elastic process are calculated,and it is found that the comb-like polymer molecules with longer backbone or shorter arm are more close to linear chains.But the arm density m affects the chain conformation non-monotonously.Some thermodynamic properties are also studied.Average Helmholtz free energy and elastic force f all increase with elongation ratioλfor all chains.     

Enhancing the ionic conductivity in a composite polymer electrolyte with ceramic nanoparticles anchored to charged polymer brushes

Polymer electrolytes a re essential for next-gene ration lithium batteries because of their excellent safety record.However,low ionic conductivity is the main obstacle restricting their commercial application.Composites with nanoparticles are a promising route to overcome this obstacle.In this work,lithium polystyrene sulfonate brushes(LiPSS)is anchored to silicon dioxide nanoparticles with chemical bonding using atom transfer radial polymerization(SI-ATRP).The composite polymer electrolytes are made by mixing vinylene carbonate and nanoparticles via a facile in situ polymerization process.The ionic conductivity of composite polymer electrolytes is improved to 7.2×10^-4 S/cm at room temperature,which is attributed to the low degree of crystallinity of polymer electrolyte and the fast ion transport on the surfaces of polymer brush layers that act as a conductive network.The composite polymer electrolytes show a wide electrochemical window of approximately 4.5 V vs.Li^+/Li and excellent cycling performance retention of approximately 95%after 100 cycles at ambient temperature.The results also prove that surface groups of ceramic na noparticles are an important way to increase the electrochemical properties of composite polymer electrolytes.     

Preparation and performance characterization of polymer Li-ion batteries using gel poly(diacrylate) electrolyte prepared by in situ thermal polymerization

A gel polymer electrolyte (GPE) was prepared by in-situ thermal polymerization of 1,3-butanediol diacrylate (BDDA) in a EC/EMC/DMC electrolyte solution at 100 °C. The GPE with 15 wt.% polymer content appears as apparently dry polymer with sufficient mechanical strength and shows a high ionic conductivity of 3.2×10^–3 S cm^–1 at 20 °C. The MCMB–LiCoO₂ type polymer Li-ion batteries (PLIB) prepared using this in-situ internal polymerization method exhibit a very high initial charge–discharge efficiency of 92.1%, and can deliver 94.4% of its nominal capacity at 1.0 C rate and 70.7% of its room temperature capacity at –20 °C. Also, the PLIB cells show very good cycling ability with >85% capacity retention after 300 cycles. The excellent charge–discharge properties of the PLIB cells are attributed to the integrated structure in which the polymer matrix spreads over entire region of the cell acting as a strong binder and electrolyte carrier to produce a stabilized electrode–electrolyte interface. In addition, the fabricating process of the polymer cell is quite simple and convenient for practical applications.     

Synthesis and characterization of new polymer systems containing very bulky tris(trimethylsilyl)methyl substituents as side chains

The 4-chloromethyl styrene (CMS) was copolymerized with different styrenic monomers such as methyl styrene, 4-methoxy styrene and α-methyl styrene by free radical polymerization method at 70 ± 1 °C using α,α^′-azobis(isobutyronitrile) (AIBN) as an initiator and the copolymers I, II and III collected respectively. The very bulky tris(trimethylsilyl)methyl {trisyl} substituents were covalently attached to the obtained copolymers with replacement of all the chlorine atoms in CMS units. The polymers, obtained in quantitative yields, were characterized by FT-IR, ¹H NMR and ¹³C NMR spectroscopy; differential scanning calorimetry (DSC) and GPC studies. All the polymers containing trisyl groups showed a high glass transition temperature (in the range 150-190 °C) in comparison with copolymers I-III (in the range 90-95 °C). The increase of the glass transition temperature reflects the substantial increase in rigidity of new polymers bearing very bulky substituents in side chains.     

Synthesis and characterization of graft copolymers containing poly(p-phenylene) main chains and mesogen-jacketed liquid-crystalline polystyrene side chains

A series of novel comblike mesogen-jacketed liquid-crystalline graft copolymers, poly(p-phenylene)-g-poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PPP-g-PMPCS) copolymers, have been designed and successfully synthesized by a Yamamoto coupling reaction and subsequent atom transfer radical polymerization (ATRP). ¹H NMR spectroscopy, ultraviolet–visible spectra, and gel permeation chromatography (GPC) have been used to confirm the molecular structure of the macroinitiator and the copolymers. A study of the polymerization kinetics of ATRP has shown that the molecular weight of the copolymer increases linearly with the conversion of the monomer, whereas the polydispersity remains narrow (≤1.28), indicating that the ATRP of 2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene is well controlled. Thermogravimetric analysis and differential scanning calorimetry (DSC) measurements have indicated that the PPP-g-PMPCS copolymers have better thermal stabilities than the macroinitiator, and their thermal stabilities increase with increasing molecular weight. The liquid-crystalline behavior has been examined with polarized optical microscopy, DSC, one-dimensional wide-angle X-ray diffraction (1D WAXD), and two-dimensional wide-angle X-ray diffraction (2D WAXD). The results show that all the comblike copolymers exhibit obvious liquid-crystalline behaviors, even though the GPC molecular weight of the segments of poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PMPCS) have been determined to be far less than the critical value of linear PMPCS. Moreover, 1D WAXD measurements show that the temperature at which the comblike mesogen-jacketed liquid-crystalline copolymers can transform into a liquid-crystalline phase is low; about 20 °C in comparison with the linear ones. 2D WAXD analysis has revealed that these comblike copolymers should be assigned to a hexatic columnar nematic (Φ_HN) phase. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2543–2555, 2007     

Preparation of a new polymer containing photoluminescent pyrazoline unit in the main chain

A novel photoluminescent polymer (PPyne) containing a 2‐pyrazoline unit in the molecular main chain was prepared (for the first time) by polycondensation between a 2‐pyrazoline monomer [an adduct of 2,6‐bis(4‐bromobenzylidene)cyclohexanone with phenylhydrazine] and 2,5‐dihexyloxy‐p‐phenylene diboric ester in the presence of Pd(PPh₃)₄. PPyne had a number‐average molecular weight of 7800 and a polydispersity index of 1.99 and showed good solubility in common organic solvents. In toluene PPyne exhibited an intrinsic viscosity [η] of 0.42 dL g^?1 at 30 °C. The polymer was photoluminescent (PL) in both the chloroform solution and the solid state; the quantum yield of PL in the solution was 40%. In the two states, PPyne gave the same ultraviolet–visible (UV–vis) peak at 368 nm and the same PL peak at 512 nm. DSC traces indicated that PPyne had a melting temperature of 168 °C, and thermogravimetric analysis revealed that the polymer had good thermal stability with a 5 wt % loss temperature of 376 °C under N₂. Electrochemical oxidation of PPyne started at about 0.5 V versus Ag/AgNO₃ and gave a peak at 0.98 V versus Ag/AgNO₃ with a color change of the film from yellow to black green. The color change was followed by UV–vis spectroscopy. The corresponding reduction peak appeared at 0.80 V versus Ag/AgNO₃. Treatment of PPyne with HCl led to dehydrogenating transformation of the polymer to a new cross‐conjugated polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2686–2697, 2004     

Synthesis of polymer containing o-nitrobenzyl ether structure in the main chain

The polycondensation of nitrated xylenedihalides with diphenols was carried out under various conditions. The polycondensation of 2-nitro-1, 3-xylylenedibromide (NXDB) with 4,4′-isopropylidenediphenol proceeded in competition with the decomposition of polymer in the mixed solvent of tetrahydrofuran (THF) and dimethylsulfoxide (DMSO). The viscosity of the resulting polymer was markedly affected by the concentration of aqueous sodium hydroxide, reaction time, and reaction temperature. When dibromomethane was used as a solvent, the polycondensation proceeded very smoothly without the decomposition to give a higher reduced viscosity polymer than that in THF-DMSO at 60°C. The polymer obtained in dibromomethane contained a very small amount of formal bonds determined from the ¹H-NMR spectrum. The formation of formal bonds seems to cause the molecular weight in increase. Furthemore, the polycondensation of NXDB with 2,2-bis (4-hydroxyphenyl) hexafluoropropane afforded high molecular-weight polyether in dibromomethane. However, either high reaction temperatures or the high concentrations of aqueous potassium hydroxide solution casused the viscosity of the resulting polymer to decrease during the polycondensation in dibromomethane. The obtained polyethers with o-nitrobenzyl groups showed relatively good solubility, and decomposed smoothly upon the irradiation with UV light. Therefore, these polymers might be useful for positive type photoresists.     

Synthesis and characterization of high molecular weight hexafluoroisopropylidene‐containing polybenzimidazole for high‐temperature polymer electrolyte membrane fuel cells

A high molecular weight, thermally and chemical stable hexafluoroisopropylidene containing polybenzimidazole (6F‐PBI) was synthesized from 3,3′‐diaminobenzidine (TAB) and 2,2‐bis(4‐carboxyphenyl) hexafluoropropane (6F‐diacid) using polyphosphoric acid (PPA) as both the polycondensation agent and the polymerization solvent. Investigation of polymerization conditions to achieve high molecular weight polymers was explored via stepwise temperature control, monomer concentration in PPA, and final polymerization temperature. The polymer characterization included inherent viscosity (I.V.) measurement and GPC as a determination of polymer molecular weight, thermal and chemical stability assessment via thermo gravimetric analysis and Fenton test, respectively. The resulting high molecular weight polymer showed excellent thermal and chemical stability. Phosphoric acid doped 6F‐PBI membranes were prepared using the PPA process. The physiochemical properties of phosphoric acid doped membranes were characterized by measuring the phosphoric acid doping level, mechanical properties, and proton conductivity. These membranes showed higher phosphoric acid doping levels and higher proton conductivities than the membranes prepared by the conventional membrane fabrication processes. These membranes had sufficient mechanical properties to be easily fabricated into membrane electrode assemblies (MEA) and the prepared MEAs were tested in single cell fuel cells under various conditions, with a focus on the high temperature performance and fuel impurity tolerance. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4064–4073, 2009     

Synthesis and structural characterization of a yttrium coordination polymer formed by bridging of an acyclic polyether

The amide-type acyclic polyether, 1,2-ethylenedioxy-bis(N-pyridin-2-ylmethyl-benzamide) (L) was synthesized and characterized by EA, IR and ¹H NMR spectroscopy. The reaction of yttrium nitrate with L produced a rare chain structural coordination polymer {[Y(NO₃)₃L(H₂O)]?·?(H₂O)} _n (1) by use of the flexible ligand L as the building blocks. The structure of 1 was determined by X-ray crystallography and thermal analysis. In 1, L, as a bidentate bridging spacer, binds two neighboring Y atoms to form a one-dimensional chain polymer. The chain polymer was further connected into the three-dimensional network by hydrogen bonding interactions.     

Synthesis and properties of polymer brushes composed of poly(diphenylacetylene) main chain and poly(ethylene glycol) side chains

Novel cylindrical polymer brushes consisting of poly(diphenylacetylene) main chain and poly(poly(ethylene glycol) methyl ether monomethacrylate) (PPEGMA) side chains were synthesized by the diphenylacetylene macromonomer or side chain initiated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether monomethacrylate (PEGMA) from an bromo isobutyryl-bearing poly(diphenylacetylene) (poly(BrDPA)) method. The diphenylacetylene macromonomer, namely, DPA-PPEGMA, were prepared by the ATRP of PEGMA from bromo isobutyryl-bearing diphenylacetylene. DPA-PPEGMA was polymerized successfully with WCl₆-Ph₄Sn catalyst to give high molecular weight polymer brushes poly(DPA-PPEGMA). Meanwhile, polymer brushes (PDPA-g-PPEGMA) were obtained by ATRP of PEGMA from poly(BrDPA). The molecular weight of the side chains of PPEGMA could be controlled simply by modulating the ATRP time. The macromonomer and polymer brushes are soluble in nonpolar solvents such as toluene and chloroform. The polymers of poly(BrDPA) and poly(DPA-PPEGMA) absorb in the longer wavelength region, with two peaks at around 370 and 414 nm. The polymers are thermally stable and exhibit double crystallization and melting peaks during the cooling and heating scans.     

Synthesis and properties of new polyimides containing flourinated alkoxy side chains

A series of new polyimides containing fluorinated alkoxy side chains are prepared from novel fluorinated alkoxy diamines. The dieletric constant at 1 kHz in the fluorinated polyimides decreases from 3.3 to 2.6 as fluorine content increases. The refractive index also changes from 1.58 to 1.48, dependent on the fluorine content. In addition, the fluorinated polyimides exhibit lower water absorption than the reference polyimides prepared from m-phenylenediamine.