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1.
The conversion of naphthalene, anthracene, and phenanthrene to polymeric material via Friedel-Crafts chemistry was investigated. Synthesis of the polymers was accomplished by: (1) self-condensation of the chloromethylated aromatic substrate in the presence of AlCl3 or SnCl4 or (2) treatment with chloromethyl ethyl ether (CMEE) and SnCl4, producing the chloromethylated substrate in situ, followed by self-condensation polymerization. Soluble or insoluble polymers were preferentially produced by varying the stoichiometry, time, or temperature of the reaction. The resulting polymers consisted of the polycyclic aromatic nuclei bridged by methylene groups. The regiochemistry of the polymer linkages was determined through the use of IR, 1H- and 13C-NMR. The polymers showed relatively high thermal and thermo-oxidative stabilities (380–495°C). © 1992 John Wiley & Sons, Inc.  相似文献   

2.
A series of crosslinked siloxane/poly(ethylene glycol) (Si–PEG) copolymers were synthesized from the reactive methoxy‐functional silicone resin (Si resin) and PEGs with different molecular weights via two kinds of crosslinking reactions during an in situ curing stage. One of the crosslinking reactions is the self‐condensation between two methoxy groups in the Si resin, and another one is an alkoxy‐exchange reaction between the methoxy group in the Si resin and the OH group in PEG. The synthesized crosslinked copolymers were characterized by Fourier transform infrared spectroscopy, DSC, and 13C NMR. The crosslinked copolymers were stable in a moisture‐free environment, but the Si? O? C linkages were hydrolyzed in humid conditions. The gel‐like solid polymer electrolytes (SPEs) were prepared by impregnating these crosslinked Si–PEG copolymers in a propylene carbonate (LiClO4/PC) solution. The highest conductivity reached 2.4 × 10?4 S cm?1 at 25 °C and increased to 8.7 × 10?4 S cm?1 at 85 °C. The conductivities of these gel‐type SPEs were affected by the content of LiClO4/PC, the molecular weights of PEGs, and the weight fraction of the Si resin. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2051–2059, 2004  相似文献   

3.
Allyl ether‐functional polycarbonates, synthesized by organocatalytic ring‐opening polymerization of the six‐membered cyclic carbonate monomer 2‐allyloxymethyl‐2‐ethyltrimethylene carbonate, were used to prepare non‐polyether polymer electrolytes. UV‐crosslinking of the allyl side groups provided mechanically stable electrolytes with improved molecular flexibility—Tg below ?20 °C—and higher ionic conductivity—up to 4.3 × 10?7 S/cm at 25 °C and 5.2 × 10?6 S/cm at 60 °C—due to the plasticizing properties of the allyl ether side groups. The electrolyte function was additionally demonstrated in thin‐film Li battery cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2128–2135  相似文献   

4.
A soluble aromatic polyimide was chloromethylated via a reaction with chloromethyl methyl ether in the presence of tin(IV) chloride to produce a new starting material for the modification of aromatic polyimides. The chemical structure of the resulting polymer was confirmed by 1H NMR and Fourier transform infrared spectroscopy. The maximum number of chloromethyl groups per repeat unit was 1.81. The chloromethylated polyimide was stable up to 250 °C and soluble in both chloroform and tetrahydrofuran. So that its utilization for further modification could be demonstrated, cinnamic acid was reacted with the formed polyimide, and it produced a new photosensitive polyimide with a cinnamoyl side chain. The photosensitivity of the resulting polyimide was investigated with ultraviolet spectroscopic methods. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 22–29, 2003  相似文献   

5.
N‐bromo‐hydantoin and N‐bromo‐5,5′‐dimethylhydantoin conjugated polystyrene beads were synthesized from chloromethyl polystyrene beads which differ in their particles size, crosslinking, nano‐micro porosity, and tunnels size on the surface, in order to study the effect of these parameters on oxidative halogen release and resultant activity, for water purification applications. The synthesized beads were characterized using elemental analysis, FT‐IR, solid state 13C‐NMR, and scanning electron microscope (SEM). The conjugation yield and kinetics in different solvents and bromine loading capacity were studied. The N‐bromoamine polystyrene beads were tested for water decontamination according to NSF 231 protocol. The release of active bromine was analyzed by spectrophotometer using a DPD‐1 kit and also studied the antimicrobial activity against Escherichia coli and MS2 phages. Bead's nano‐micro characteristics were found critical for oxidative halogen release control: rate stabilization and modulation, extension and also influences antimicrobial activity. The synthesized beads exhibited extended and stable release of bromine, 6 and 4 log reduction for E. coli and MS2, respectively for 250 L of passing contaminated water. Thus, N‐halamine hydantoins conjugated polystyrenes, chemically or kinetically release modified should have applications as disinfectants in water purification systems as well as medical field. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 596–610  相似文献   

6.
Various star‐shaped poly(phenoxy propylene sulfide)s (PPSs) bearing curable end groups were synthesized by the functionalization of the propagating ends of star‐shaped poly(PPS) with various electrophilies. The functionalization with chloromethyl styrene proceeded quantitatively, and afforded polymers with Mn almost agreed with theoretical value and narrow Mw/Mn. The photocuring conditions were optimized, and the addition of 10 wt % of poly(ethylene glycol) diacrylate was effective to attain sufficient crosslinking. The photocuring reaction of the end‐functionalized poly(PPS) films cast on silicon wafers was conducted by UV irradiation. The cured poly (PPS)s became insoluble in THF, supporting the sufficient crosslinking. Developing of a cured polymer yielded a negative photoresist pattern. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010  相似文献   

7.
Novel crosslinkable fluorinated oligoimides were prepared in two steps. The first involved the synthesis of oligoimides terminated with nadic or allylic double bonds, and the second step was materialized either by a radical addition of mercaptotrialkoxysilane derivatives onto nadic double bonds or a hydrosilylation reaction of hydrogenotrialkoxysilane derivative onto allylic double bonds. Three kinds of crosslinking of the trialkoxysilane end groups were studied. The first kind entailed a thermal self‐crosslinking of trialkoxysilane groups. The second process of crosslinking incorporated a bicomponent system—the crosslinked agent was 1,1,1‐tris(4‐hydroxyphenyl)ethane (TRIOH). The trialkoxysilane groups reacted with the hydroxyl–phenol groups of TRIOH to give thermally stable phenoxysilane bonds as well as a crosslinking network. The last method was also a bicomponent system; the oxalic acid was added into an oligoimide solution where by thermal treatment water was created. The water molecules hydrolyzed the trialkoxysilane groups into silanol groups that polycondensed into a crosslinked network following a sol–gel process. The mechanism of the different crosslinking reactions was investigated by Fourier transform infrared spectroscopy and solid‐state 29Si NMR. The self‐crosslinked material prepared from precursor α,ω‐trimethoxysilyl fluorinated oligomer (Mn = 5500 g · mol?1) exhibited a 10 wt % loss temperature under air higher than 420 °C and a low birefringence (Δn = 0.008) at 1.300 μm. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2602–2619, 2001  相似文献   

8.
The quasi‐living cationic copolymerization of 3,3‐bis(chloromethyl)oxetane (BCMO) and ε‐caprolactone (ε‐CL), using boron trifluoride etherate as catalyst and 1,4‐butanediol as coinitiator, was investigated in methylene chloride at 0°C. The resulting hydroxyl‐ended copolymers exhibit a narrow molecular weight polydispersity and a functionality of about 2. The reactivity ratios of BCMO (0.26) and ε‐CL (0.47), and the Tg of the copolymers, indicate their statistical character. The synthesis of poly(3,3‐bis(azidomethyl)oxetane‐co‐ε‐caprolactone) from poly(BCMO‐co‐ε‐CL) via the substitution of the chlorine atoms by azide groups, using sodium azide in DMSO at 110°C, occurs without any degradation, but the copolymers decompose at about 240°C. All polymers were characterized by vapor pressure osmometry or steric exclusion chromatography, 1H‐NMR and FTIR spectroscopies, and DSC. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1027–1039, 1999  相似文献   

9.
1,3‐Dithiane and its derivatives are widely used as powerful acyl anion equivalent to a range of useful transformations that are needed in the synthesis of natural products. In this work, a series of polyolefins containing pendant dithiane groups have been designed and synthesized via acyclic diene metathesis polymerization (ADMET) polymerization and subsequent hydrogenation. The structures of these polymers were characterized by 1H NMR, 13C NMR, and FT‐IR, and successful incorporation of the dithiane groups was proved. With different contents of the dithiane moieties, these ADMET polymers exhibited distinct thermal properties different from each other as evidenced by differential scanning calorimetry and thermal gravimetric analysis. The dithiane units in the ADMET polymer with 20 methylene carbons between the adjacent dithiane groups were transformed into thiol groups via reaction with Bu3SnH. This work provided a convenient route to synthesize polyethylene with pendant thiol groups that are evenly distributed in the chain. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2468–2475  相似文献   

10.
Two different gel‐type resins have been prepared by suspension polymerization using 2 wt % divinylbenzene (DVB) with either p‐vinylbenzyl chloride (pVBC) or a mixture of VBC isomers (~ 70% m‐; ~ 30% p‐). Significant difference in the chlorine content was observed, which was attributed to a more favored hydrolysis process when p‐VBC was used. The presence of hydroxyl groups has been confirmed by elemental microanalytical data and solid‐state 13C cross‐polarization/magic angle spinning (CP‐MAS) nuclear magnetic resonance (NMR) spectra. Hypercrosslinked resins were prepared from both gel‐type precursors by treatment with FeCl3 in 1,2‐dichloroethane (DCE) at 80 °C. The resultant resins showed differences in specific surface area and degree of hydrophilicity. The performance of the hypercrosslinked resins was evaluated in solid‐phase extraction (SPE) of polar compounds, and better results were obtained for the hypercrosslinked resin prepared from p‐VBC that combines a relatively high specific surface area (908 m2 g?1) and somewhat higher oxygen content (3.96 wt % O). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1718–1728, 2005  相似文献   

11.
Typically, phenylethynyl (PE) end‐capped oligomides require a temperature of 370 °C for 1 h to develop a crosslinked system. A published method using poly(ethylene glycol)s (DM‐PEG‐250 and PEG‐400) as cosolvents with NMP was effective in crosslinking the ethynyl end‐caps at 250 °C/3 h in nonsulfonated oligomides. The application of this novel crosslinked method to PE end‐capped sulfonated oligomides was effective but caused a secondary crosslinked network via the sulfonic acid groups and ethylene glycol solvents. The solid‐state 13C NMR spectral data on 13C‐labeled end‐caps in the PE‐3F‐SPI‐3 oligomide provide evidence for the ethynyl to ethynyl and ethylene oxide sulfonate ester dual crosslinked structure. Infrared spectroscopy of model compounds also provides evidence for the presence of crosslinked sulfonate ester and appended sulfonate ester side chains. 13C NMR also provided quantitative data on the extent of the ethynyl to ethynyl crosslinking reaction and sulfonate ester crosslinks and side chains. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

12.
Poly(styrene‐graft‐ethyl methacrylate) graft copolymer was prepared by atom transfer radical polymerization (ATRP) with poly(styrene‐cop‐chloromethyl styrene)s in various compositions as macroinitiator in the presence of CuCl/1,2‐dipiperidinoethane at 130 °C in N,N‐dimethylformamide. Both macroinitiators and graft copolymers were characterized by elemental analysis, IR, 1H and 13C NMR, and differential scanning calorimetry. 1,2‐Dipiperidinoethane was an effective ligand of CuCl for ATRP in the graft copolymerization. The controlled growth of the side chain provided the graft copolymers with polydispersities of 1.60–2.05 in the case of poly(styrene‐cop‐chloromethyl styrene) (62:38) macroinitiator. Thermal stabilities of poly(styrene‐graft‐ethyl methacrylate) graft copolymers were investigated by thermogravimetric analysis as compared with those of the macroinitiators. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 668–673, 2003  相似文献   

13.
The free‐radical polymerization of styrene with p‐nitrobenzyl triphenyl phosphonium ylide as an initiator in dioxane at 80 ± 1 °C in a dilatometer under a nitrogen atmosphere for 150 min resulted in a syndiotactic polymer, as evidenced by IR, 1H NMR, and 13C NMR spectroscopy. A 1H NMR spectrum showed methylene protons as triplets; 13C NMR signals of the phenyl ipso carbons were used for the determination of the tacticity. The system followed ideal kinetics. Gel permeation chromatography data were used evaluate the weight‐average molecular weight. The overall activation energy was 47 kJ/mol. Electron spin resonance spectroscopy confirmed the initiation by the phenyl radical obtained by the dissociation of the ylide and the free‐radical mode of polymerization. Differential scanning calorimetry studies showed the glass‐transition temperature of the polymer to be 342 K. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6524–6533, 2005  相似文献   

14.
The new thermal radical initiators (TRIs) with linear and cyclic type groups based on derivatives of O‐imino‐isourea have been designed and synthesized. The radical polymerization property of the synthesized TRI derivatives as a radical initiator in n‐butyl acrylate was monitored by differential scanning calorimetry analysis. TRI derivatives with linear type groups, such as 3‐PenDCC, 3‐HexDCC, and 4‐HepDCC, showed peak temperatures (Tpeak) of 80–84 °C, whereas those with cyclic type groups, such as C‐PenDCC, C‐HexDCC, and C‐HepDCC, exhibited a wide Tpeak distribution in the 74–87 °C range. The polymerization efficiency using new TRIs in n‐butyl acrylate was elaborately identified from the molecular weights and conversion obtained using gel permeation chromatography analysis and NMR spectroscopy. To consider their possible application to automotive clearcoats, the real‐time evolution of the rheological properties of clearcoat resins during the crosslinking process with newly synthesized TRI derivatives was measured, confirming the different crosslinking kinetics of TRI derivatives in real thermal curing process. The results were found to be well correlated with data from the radical polymerization experiments of TRIs. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3593–3600.  相似文献   

15.
Hyper‐cross‐linked resins stemming from a gel‐type poly‐chloromethylated poly(styrene‐co‐divinylbenzene) resin (GT) have been investigated by a multi‐methodological approach based on elemental analysis, scanning electron microscopy, X‐ray microanalysis, and solvent absorption. The hyper‐cross‐linking of the parent resin was accomplished by Friedel–Crafts alkylation of the phenyl rings of the resins with the chloromethyl groups. This produced a permanent pore system comprising both micropores (<2.0 nm in diameter) and mesopores (2.2 nm). The chloromethyl groups that did not react in the hyper‐cross‐linking step were transformed into methylmercaptan groups and the latter were then converted into sulfonic groups by oxidation with hydrogen peroxide. By this procedure the extensive permanent porosity of the parent unsulfonated hyper‐cross‐linked polymer (HGT) was retained by the sulfonated polymer (HGTS). The final exchange capacity of HGTS was determined to be 0.36 mmol g?1. HGTS was easily metalated with PdII and the subsequent reduction of the metal centers with either aqueous sodium borohydride, formaldehyde, or dihydrogen produced three Pd0/HGTS nanocomposites. The metal nanoparticles had diameters in the 1–6 nm range for all the nanocomposites, as determined by TEM, but with somewhat different distributions. When formaldehyde was used, more than 90 % of the nanoparticles were less than 3 nm and their radial distribution throughout the polymer beads was quite homogeneous. These findings show that with this reducing agent the metal nanoparticles are generated within the pore system of the polymer matrix, hence their size is controlled by the dimensions of the pores of the polymeric support.  相似文献   

16.
High‐capacity or high‐power‐density capacitors are being actively investigated for portable electronics, electric vehicles, and electric power systems. The dielectric nanocomposite with a small loading of carboxylic polystyrene (PS‐COOH) nanoparticles in poly(vinylidene fluoride‐chlorotrifluoroethylene) [P(VDF‐CTFE)] matrix, followed by chemical crosslinking has been described. Combination of these two methods significantly improved the capacity of electric energy storage at low electric field. Specially, the nanocomposite with 2 wt % nanoparticles and 15 wt % crosslinking agent achieved a dielectric constant of 17.2 and a discharged energy density of 17.5 J/cm3 (4.9 Wh/L) at an electric field as high as 324 MV/m, while corresponding values for pristine P(VDF‐CTFE) are 9.6 and 13.3 J/cm3 (3.7 Wh/L), respectively. Fundamental physics underlying the enhancement in the performance of the nanocomposites with respect to P(VDF‐CTFE) is illustrated by solid‐state 19F nuclear magnetic resonance of direct excitation or 19F{1H} cross polarization. It revealed different dynamics behavior between crystalline/amorphous regions, and PS‐COOH nanoparticles favored the formation of polar γ‐form crystals. Small‐angle X‐ray scattering studies revealed the contribution of the interface to the extraordinary storage of electric energies in the nanocomposites. This approach provided a facile and straightforward way to design or understand PVDF‐based polymers for their practical applications in high‐energy‐density capacitors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1160–1169  相似文献   

17.
A relatively low‐temperature crosslinking method for phenylethynyl (PE) end‐capped oligomides was developed. PE end‐capped oligomides are typically cured into crosslinked polyimides at 370 °C for about 1 h. The addition of a low viscosity mixed‐solvent of N‐methylpyrrolidinone (NMP)/dimethyl ether of polyethylene glycol (M = 250 g/mol), NMP/DM‐PEG‐250, or NMP/polyethylene glycol (M = 400 g/mol), NMP/PEG‐400, as film forming medium for PE‐end‐capped oligomides was investigated. Fourier transform infrared spectroscopy and 13C NMR showed that the mixed solvent addition was effective for achieving low‐temperature crosslinking of the ethynyl end‐caps over the temperature range 200–250 °C. The low temperature crosslinking process was explained by thermolysis of the PEG molecules over this temperature range forming free radical species such as ~CH2CH2O· or ~CH2CH2· which initiate cure of the ethynyl groups resulting in a cross linked polyimide membrane. The PEG solvents also provide a radical source for the degradation polymerization of the solvents to a water and NMP insoluble polymer, which formed a miscible blend with the crosslinked membrane. Glass transition temperature (differential scanning calorimetry) data and thermo gravimetric analysis data provide evidence for the miscible blend. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3950–3963, 2010.  相似文献   

18.
A new class of linear unsaturated polyphosphate esters based on divanillylidene cyclohexanone possessing liquid crystalline‐cum‐photocrosslinkable properties have been synthesized from 2,6‐bis[n‐hydroxyalkyloxy(vanillylidene)]cyclohexanone [n = 6,8,10] with various alkyl/aryl phosphorodichloridates in chloroform at ambient temperature. The resultant polymers were characterized by intrinsic viscosity, FT‐IR, 1H, 13C, and 31P‐NMR spectroscopy. All the polymers showed anisotropic behavior under hot stage optical polarized microscope (HOPM). The liquid crystalline textures of the polymers became more transparent with increasing spacer length. The thermal behavior of the polymers was studied by thermogravimetric analysis and differential scanning calorimetry. The Tg, Tm, and Ti of the polymers decreased with increasing flexible methylene chain. The photocrosslinking property of the polymer was investigated by UV light/UV spectroscopy; the crosslinking proceeds via 2π‐2π cycloaddition reactions of the divanillylidene exocyclic double bond of the polymer backbone. The pendant alkyloxy containing polymers show faster crosslinking than the pendant phenyloxy containing polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5215–5226, 2004  相似文献   

19.
Generally, protection and deprotection procedures of amino groups are required in preparing propargyl ether‐containing benzoxazines. In this study, we report a facile, deprotection‐free preparation of a propargyl ether‐containing phosphinated benzoxazine (2) from the nucleophilic substitution of a phenolic OH‐containing phosphinated benzoxazine (1) and propargyl bromide in the catalysis of potassium carbonate. The structure of (2) was characterized and confirmed by a high‐resolution mass spectrum, 1H, 13C, 1H‐1H, 1H‐13C nuclear magnetic resonance (NMR) spectra, and X‐ray single crystal diffractogram. infrared (IR) and differential scanning calorimetry were used to monitor the ring‐opening of benzoxazine and crosslinking of propargyl ether. The microstructure and the structure–property relationship of the resulting homopolymers and copolymers are discussed. The Tg of homopolymer of (2) is 208 °C by dynamic mechanical analysis, the coefficient of thermal expansion is 43 ppm/°C, and Td 5% (N2) is 393 °C, respectively, which are higher than those of the homopolymer of (1) . Similar trends were observed in the copolymerization system. The results demonstrate the beneficial effect of crosslinking afforded by the propargyl ether group is higher than that by the phenolic OH group. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

20.
Conductive composites consisted of epoxy resin and polyanilines (PANIs) doped with dodecylbenzenesulfonic acid ( 1 ), dodecylsulfonic acid (2), di(2‐ethylhexyl)sulfosuccinic acid (3), and HCl were synthesized by use of Ntert‐butyl‐5‐methylisoxazolium perchlorate (5) under various reaction conditions. It was found that the composites with PANI doped with acid 2 (PANI‐2) prepared by curing with 10 mol % of reagent 5 at 80 °C for 12 h showed high electroconductivity along with the low conducting percolation threshold (3 wt % of PANI‐2). Furthermore, the composite with even ?10 wt % of PANI‐2 exhibited ?10?1 S/cm of electroconductivity. The UV–vis and IR measurements indicated that the conductive emeraldine salt form of PANI‐2 in the composite was maintained after the curing reaction. The thermal stability was studied by TGA and DSC measurements, and then, the Td10 and Tg of the composite with 5 and 10 wt % of PANI‐2 were found to be similar to those with the cured epoxy resin itself. In addition, the similar investigation with an oxetane resin instead of the epoxy resin was also carried out. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 718–726, 2006  相似文献   

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