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1.
Poly(o‐methyl‐acrylamideyl‐benzoic acid)‐ZnS (P(o‐MAABA)‐ZnS) nanocomposites have been prepared and characterized. The resultant P(o‐MAABA)‐ZnS nanocomposites in solution show two emissions in the purple‐light area (370 nm) and in the blue‐light area (425 nm), which are assigned to the polymer and ZnS nanoparticles, respectively. The coordination between the polymer and Zn2+ and the surface chemical composition has been studied by Infrared spectroscopy and X‐ray photoelectron spectroscopy (XPS). The particle size of ZnS nanoparticles was homogeneous and the average size was 3.8 nm, which were characterized by UV absorption spectrum and X‐ray Diffraction. The P(o‐MAABA)‐ZnS composites displays good film formability and the films also show two emissions in 370 and 425 nm. After doped with Tb3+, there was effective energy transfer from ZnS nanoparticles to Tb3+. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

2.
The effects of UV irradiation on iron(III)chloride doped poly(vinyl alcohol) (PVA) films, using a high molar mass polymer, have been studied. It has been found that the polymer is oxidized and crosslinked during UV irradiation. UV/VIS spectra reveal an exponential loss of absorption at λ = 360 nm, and the refractive index of the PVA:FeCl3 films decreases significantly during UV irradiation (ΔnD = ?0.09). The effects of crosslinking have been studied using the sol–gel technique, which revealed high gel contents due to doping and UV‐exposure. Photolithographic patterning of doped PVA films using a medium‐pressure mercury‐vapor UV source has been carried out, leading to good contrast behavior before and after development in aqueous media. A photobleaching effect was observed, therefore the curing of thicker films is feasible. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

3.
In this study, α,ω‐bis(3‐(1‐methoxy‐2‐hydroxypropoxy)propyl)polydimethylsiloxane and α‐N,N‐dihydroxyethylaminopropyl‐ω‐butylpolydimethylsiloxane were used to prepare block and graft waterborne polyureathane–polysiloxane copolymer dispersions. α,ω‐bis(3‐(1‐methoxy‐2‐hydroxypropoxy)propyl)polydimethylsiloxane was synthesized by hydrosilylation, methoxylation and equilibrium reactions; α‐N,N‐dihydroxyethylaminopropyl‐ω‐butylpolydimethylsiloxane was synthesized via hydroxyl protection, alkylation, anionic ring‐opening polymerization, hydrosilylation, and deprotection. Block and graft waterborne polyurethane–polysiloxane copolymer dispersions were prepared by the reaction of poly(propylene glycol) (PPG), toluene diisocyanate (TDI), 2,2‐dimethylol propionic acid (DMPA), 1,4‐butanediol (BDO), α,ω‐bis(3‐(1‐methoxy‐2‐hydroxypropoxy)propyl)polydimethylsiloxane, and α‐N,N‐dihydroxy‐ethylaminopropyl‐ω‐butylpolydimethylsiloxane. The water absorption of block and graft waterborne polyurethane–polysiloxane copolymer films decreased from 163.9 to 40.2% and 17.3%, respectively, when percent of polysiloxane (w/w) increased from 0 to 5%, and the tensile strength of the block waterborne polyurethane–polysiloxane copolymer films decreased while the tensile strength of graft waterborne polyurethane–polysiloxane copolymer films increased with increase of percent of polysiloxane. For graft waterborne polyurethane–polysiloxane films, the tensile strength would decrease when percent of polysiloxane was more than 3%. POLYM. ENG. SCI., 54:805–811, 2014. © 2013 Society of Plastics Engineers  相似文献   

4.
Poly(3‐methlthiophene) films were prepared under “silent” and “sono‐electrochemical” potentiostatic (SEP) conditions. A three‐electrode one‐compartment sono‐cell was used with a working platinum disc electrode. The sono‐electrochemically formed polymer films were deposited with different working electrode‐to‐horn distances. The composition, electrochemical, spectroscopic, and morphological characteristics of the resulting polymer films were determined. Elemental analysis, FTIR‐spectra, and X‐ray photoelectron spectroscopy (XPS) data proved that the polymer films prepared under SEP conditions have predominant α‐α′‐couplings between the 3MT units, and the aromatic ring integrity is maintained in the film. Scanning electron microscopy showed that those films are more compact and less porous compared to the films prepared under silent conditions. The use of sono‐irradiation during electropolymerization enhanced the diffusion of the monomer units towards the electrode surface and resulted in relatively less doped polymers with less conductivity. Electrochemical impedance spectroscopy (EIS) data for films prepared under silent and SEP conditions were collected in a monomer‐free solution. The results show that the impedance of SEP films is relatively higher than those prepared under silent conditions, and a combination of charge transfer kinetics with diffusion‐controlled conduction mechanism within the films. The diffusion was found to be a function of the porosity of the film. Conductivity measurements are in good agreement with EIS, elemental analysis, and XPS data. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2416–2425, 2006  相似文献   

5.
As an alternative to petroleum‐based polyol, hydroxyl containing material was prepared from linseed oil for polyurethane synthesis. Hexamethylene di‐isocyanate (HMDI) and/or 4, 4′‐methylene diphenyl di‐isocyanate (MDI) were used as isocyanate source. The polymerization reaction was carried out without catalyst. Polymer films were prepared by casting‐evaporation technique. The MDI/HMDI‐based polyurethane and its films had higher Tg and better thermal property than that of the HMDI‐based one because of the existence of benzene ring in the polymer chain. Static water contact angle was determined to be 74° and 77.5° for HMDI and MDI/HMDI‐based films, respectively. Water adsorption was found to be around 2.6–3.6% for both films. In vitro degradation of polyurethanes in phosphate buffered saline at 37°C was investigated by gravimetric method. Fourier transform infrared spectroscopy and scanning electron microscopy were used for confirmation of degradation on the polymer surface. The degradation rate of the HMDI‐based polyurethane film was found higher than that of the MDI/HMDI‐based film. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films, and the polyurethane films investigated here was not cytotoxic. Silver‐containing films were prepared using Biocera A® as filler and were screened for their antibacterial performance against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and/or Bacillus subtilis. The films prepared with and without Biocera A® exhibited antibacterial activity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

6.
Novel, polymeric UV‐to‐visible converters were prepared by doping elastomeric poly(ether‐urethaneurea) copolymers with 5–25% by weight of ErCl3 6H2O, corresponding to Er3+ concentrations of 2.19 to 10.86% by weight. When excited in the UV at 355 nm, the doped films generated a very broad, continuous visible luminescence between 400 and 750 nm. Preparation and spectroscopic characterization of the samples are discussed in detail. The color coordinates, color temperature, color rendering index of the samples, and the degree of overlap of their emission bands with the spectral response of the eye were determined. The color rendering index of samples is in the 57–70 range. The sample containing 2.19% by weight of Er3+ was found to give the color coordinates closest to the white‐source region and the highest color rendering index. The color temperatures of the samples were in the 5093–5540 K range. Overlap between the emission bands and the spectral response of the eye improved with increasing erbium concentration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

7.
A new electrochoromic polymer poly(8,11‐bis(3,4‐ethylenedioxy thiophen‐2‐yl)acenaphtho[1,2‐b]‐quinoxaline) (PBEAQ) was synthesized by electrochemical polymerization of the corresponding monomer (BEAQ) in a 0.1 M tetraethylammonium tetrafluoroborate (TEABF4) dichloromethane–acetonitrile (2 : 1, v : v) solution. The monomer and polymer were characterized by elemental analysis, 1H‐NMR, IR, and UV‐vis spectroscopy. The electrochemical and optical properties of polymer were investigated by cyclic voltammetry and UV‐vis spectroscopy. Cyclic voltammetry and spectroelectrochemistry studies demonstrated that the polymer can be reversibly reduced and oxidized (both n‐ and p‐doped) between ?2 V and +1.5 V vs. Ag/Ag+. The polymer had a transmissive light blue color in the oxidized state and reddish color in the reduced state. Undoped polymer shows UV‐vis absorption peaks at 615 nm in solution, 650 nm in solid state, and has an optical band gap of 1.5 eV. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

8.
Stable pure‐blue electroluminescence (EL) is obtained from polymer light‐emitting devices by dispersing poly(9,9‐dioctylfluorene) (PFO) into a wide band‐gap mixed‐matrix of poly(9‐vinylcarbazole) (PVK):2‐(4‐biphenylyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole (PBD). From the EL spectra of the PFO‐doped films, we find that the additional green emission observed in the EL spectra of the pure PFO devices was significantly suppressed in the PFO‐doped devices. The spectral stability was also improved through evaluating the EL spectra of the PFO‐doped films annealed at different temperatures (from 80 to 150 °C). These results demonstrate that doping of PFO into a matrix to weaken the aggregate and oxidation of the PFO molecules is a simple strategy to suppress the green emission. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44950.  相似文献   

9.
A new diamine, 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐diaminodiphenyl ether (FPAPE) was synthesized through the Suzuki coupling reaction of 2,2′‐diiodo‐4,4′‐dinitrodiphenyl ether with 3,4,5‐trifluorophenylboronic acid to produce 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐dinitrodiphenyl ether (FPNPE), followed by palladium‐catalyzed hydrazine reduction of FPNPE. FPAPE was then utilized to prepare a novel class of highly fluorinated all‐aromatic poly(ether‐imide)s. The chemical structure of the resulting polymers is well confirmed by infrared and nuclear magnetic resonance spectroscopic methods. Limiting viscosity numbers of the polymer solutions at 25 °C were measured through the extrapolation of the concentrations used to zero. Mn and Mw of these polymers were about 10 000 and 25 000 g mol?1, respectively. The polymers showed a good film‐forming ability, and some characteristics of their thin films including color and flexibility were investigated qualitatively. An excellent solubility in polar organic solvents was observed. X‐ray diffraction measurements showed that the fluoro‐containing polymers have a nearly amorphous nature. The resulting polymers had Tg values higher than 340 °C and were thermally stable, with 10% weight loss temperatures being recorded above 550 °C. Based on the results obtained, FPAPE can be considered as a promising design to prepare the related high performance polymeric materials. Copyright © 2011 Society of Chemical Industry  相似文献   

10.
The photocoloration of a novel spirooxazine, 1-[β-(4-trifluoromethyl benzoyloxy)ethyl]-3,3-dimethyl-spiro[indoline-2,3′-[3H]-naphtho[2,1-b]-1,4-oxazine] (SO), doped in different polymer films and fibers was studied. The results show that photocoloration increased with increasing concentration of spirooxazine in polymer films. The photocoloration rate of spirooxazine in PMMA is faster than that in PS due to the polarity of the polymer films. A general model for the kinetics of photocoloration of spirooxazine in polymer films is proposed. The results also show that the photocoloration rate of spirooxazine in PET is faster than that in Nylon-6 due to the crystallinity of the polymer fibers.  相似文献   

11.
The color development due to the complex formation of poly(vinyl alcohol) (PVA) with iodine increased with increasing syndiotacticity of PVA. Isotactic PVA showed no color development. The color development of syndiotacticity-rich PVA film decreased with increasing annealing temperature for films before complexization, whereas that of atactic (commercial) PVA increased with it. Lower temperatures, the elongation of complex film, and the presence of boric acid enhanced the absorbance at 600 nm due to I?5. The complexes are assumed to be made by incorporation of polyiodines into aggregates of syndiotactic sequences in PVA. The polarizability and electric conductivity of complex films are investigated. © 1993 John Wiley & Sons, Inc.  相似文献   

12.
Latex films were prepared by annealing pyrene (Py)‐labeled poly(methyl methacrylate) particles at glass‐transition temperature (100°C). These films were then irradiated by γ‐rays from 60Co in a gamma cell at room temperature at the same dose rate (rad/h) for 30 min. Before dissolution films were annealed at elevated temperatures for a 30‐min time interval to complete the film formation process. Steady‐state fluorescence (SSF) technique were used to monitor the dissolution of these irradiated latex films. The dissolution of films in chloroform–heptane (80–20%) mixture was monitored in real time by the Py fluorescence intensity change. Relaxation constants k0 and desorption coefficients Dd of polymer chains were measured. It was observed that both Dd and k0 values first increased and then decreased by increasing the annealing temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 129–137, 2002  相似文献   

13.
A soluble n‐type π‐conjugated polymer ( polymer 1 ) composed of a 1,2,4‐triazole ring substituted by a 4‐n‐octylphenyl subunit at the 4‐position of the 1,2,4‐triazole ring and pyridine‐2,5‐diyl rings was synthesized by Ni(cod)2 (cod = 1,5‐cyclooctadiene) promoted dehalogenation polycondensation of 3,5‐bis(2‐bromopyridyl)‐4‐n‐octylphenyl‐1,2,4‐triazole ( monomer 1 ). A polymer complex ( polymer‐BiCl3 ) was synthesized by the reaction of polymer 1 with BiCl3. The UV–vis spectrum of polymer 1 exhibited an absorption maximum (λmax value) at a longer wavelength than that exhibited by monomer 1 revealing that its π‐conjugation system was expanded along the polymer chain. Polymer 1 was electrochemically active in film, and the electrochemical reaction was accompanied with electrochromism. Thermoelectoric properties of polymer 1 and polymer‐BiCl3 were investigated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39928.  相似文献   

14.
A series of new, organosoluble, and light‐colored poly(amide imide imide)s were synthesized from tetraimide dicarboxylic acid ( I ) and various aromatic diamines by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. I was prepared by the azeotropic condensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4′‐oxydianiline at a 2/2/1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP)/toluene. The thin films cast from N,N‐dimethylacetamide (DMAc) had cutoff wavelengths shorter than 400 nm (365–394 nm) and color coordinate b* values between 13.10 and 36.07; these polymers were lighter in color than the analogous poly(amide imide)s and isomeric polymers. All of the polymers were readily soluble in a variety of organic solvents, including NMP, DMAc, N,N‐dimethylformamide, dimethyl sulfoxide, and even less polar dioxane and tetrahydrofuran. The cast films exhibited tensile strengths of 90–104 MPa, elongations at break of 7–22%, and initial moduli of 1.9–2.4 GPa. The glass‐transition temperatures of the polymers were recorded at 274–319°C. They had 10% weight losses at temperatures beyond 520°C and left more than a 50% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 669–679, 2003  相似文献   

15.
A novel aromatic diamine, 1,1‐bis(4‐amino‐3,5‐dimethylphenyl)‐1‐(3,4,5‐trifluorophenyl)‐2,2,2‐trifluoroethane, containing a pendant polyfluorinated phenyl group, a trifluoromethyl group, and methyl groups ortho‐substituted to the amino groups in the structure was synthesized and characterized. The diamine was polymerized with several aromatic dianhydrides, including 3,3′,4,4′‐biphenyltetracarboxylic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, 4,4′‐oxydiphthalic anhydride, and 4,4′‐hexafluoroisopropylidene diphthalic anhydride, via a high‐temperature one‐step procedure to afford four polyimides (PIs) with inherent viscosities of 0.47–0.70 dL/g. The PIs exhibited excellent solubilities in a variety of organic solvents. They were soluble not only in polar aprotic solvents but in many common solvents, such as cyclopentanone, tetrahydrofuran, and even toluene at room temperature. The tough and flexible PI films cast from the PI solutions exhibited good thermal stabilities and acceptable tensile properties. The glass‐transition temperatures were in the range 312–365°C, and the 5% weight loss temperatures were all higher than 480°C in nitrogen. The films had tensile strengths in the range 76–99 MPa, tensile moduli of 2.2–2.8 GPa, and elongations at break of 5–8%. In addition, the PI films exhibited excellent transparency in the visible light region with cutoff wavelength as low as 302 nm and transmittance higher than 88% at the wavelength of 450 nm. The PI films showed low dielectric constants ranging from 2.50–2.68 and low moisture absorptions of less than 0.56%. The good combined properties of the PIs mainly resulted from the synergic effects of the different substituents. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

16.
The randomly distributed dopant effects in nanocrystalline samaria‐doped ceria (SDC) interlayers were investigated by systematically varying the dopant distributions and grain‐boundary densities via post‐annealing process. Electrochemical analysis demonstrates that films having lower annealing or fabrication temperatures exhibit superior surface oxygen kinetics, particularly in the case of oxygen reduction reactions (ORRs). Further investigation through TEM‐EELS shows that the typical segregation of dopants is not significantly present in SDC film deposited via the RF sputtering method, while post‐annealed SDC film shows strong dopant accumulation near the grain boundary. The results indicate that the randomly distributed dopants, in addition to the nano grains, may further enhance surface reactions by providing more preferential reaction sites due to a higher content of defects at the interface.  相似文献   

17.
A two‐part study utilizing isotactic poly(4‐methyl‐1‐pentene) (PMP) was undertaken to investigate a three‐stage process (melt‐extrusion/annealing/uniaxial stretching) (MEAUS) utilized to produce microporous films. In this report, the thermal‐annealing (second stage) and subsequent uniaxial‐stretching (third stage) results of selected PMP films from three resins, labeled A, B, and C, are discussed. From sequential analysis of the effect each stage had on the resulting microporosity, it was discovered that the melt‐extruded precursor morphology and orientation, as a consequence of the first‐stage extrusion parameters and resin characteristics, were crucial to controlling the membrane permeability. The annealing parameters were also critical, where a temperature of 205°C applied for 20 min under no tension was the optimum annealing condition for producing highly microporous PMP films upon stretching. For the conditions studied, the stretching parameters that were found to be the optimum for producing the desired characteristics in the final film were cold‐ and hot‐stretch temperatures of 70 and 180°C, respectively. The cold‐ and hot‐stretch extension levels concluded to be the best were a cold‐stretch extension of 80%, followed by hot stretching to 90%, and, thus, a total overall extension level of 170% for the processing window studied. However, these results were only with respect to resin A films, while resin B and C samples could not be produced into microporous films via the MEAUS process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1076–1100, 2002; DOI 10.1002/app.10395  相似文献   

18.
A series of poly(ether imide)s (PEIs) with light colors and good mechanical properties were synthesized from 2,5‐bis(3,4‐dicarboxyphenoxy)biphenyl dianhydride and various aromatic ether–diamines via a conventional two‐step polymerization technique that included ring‐opening polyaddition at room temperature to poly(amic acid)s (PAAs) followed by thermal imidization. The precursor PAAs had inherent viscosities ranging from 0.71 to 1.19 dL/g and were solution‐cast and thermally cyclodehydrated to flexible and tough PEI films. All of the PEI films were essentially colorless, with ultraviolet–visible absorption cutoff wavelengths between 377 and 385 nm and yellowness index values ranging from 10.5 to 19.9. These PEIs showed high thermal stabilities with glass‐transition temperatures of 206–262°C and decomposition temperatures (at 10% weight loss) higher than 478°C. They also showed low dielectric constants of 3.39–3.72 (at 1 MHz) and low water absorptions below 0.85 wt %. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

19.
Formation of porous films from poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) using the breath figures (BF) method was investigated by evaporating solutions in chloroform in humid air and examining film structure using optical and scanning electron microscopy (SEM). BF films were successfully fabricated from PHB (Mw = 486,000 g/mol) and displayed hexagonal arrays of pores, which varied in diameter (D = 7–2 μm) with solution concentrations (0.5–2.00%). SEM of fractured films also showed subsurface closed nano‐pores (D = 500–700 nm). BF films cast from PHBV (5% HV) formed arrays with smaller pores and apparent surface defects. Differential scanning calorimetry showed that porous PHB and PHBV films produced using the BF method were more crystalline than nonporous solvent cast films of PHB and PHBV. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers  相似文献   

20.
Imide units are incorporated into thermoplastic and solvent‐based polyurethane (PU) chains to improve the thermal stability of PU. However, these poly(urethane‐imide) (PUI) materials have poor processablity and suffer from solvent emission. To prepare easily processable and environmentally friendly PUI products, some waterborne PUIs are synthesized using a prepolymer process. A series of PUI dispersions with 25 wt % solid content, viscosities of 7.5–11.5 cps, and particle sizes of 63–207 nm was prepared. The composition–property relationship of PUIs, including the solubility behavior of PUI cast films, and their thermal and mechanical properties were established. The solvent resistance and tensile strength of PUI film increased with the number of imide groups. All PUIs exhibited improved thermal stability but not char yield as the temperature increased. The inclusion of a little imide increased the decomposition temperature of PUI while maintaining the elasticity of the polymer, revealing successful translation of PUI into the water‐based form. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

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