共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
二甲基苯胺等离子体聚合及聚合物结构与性能的研究 总被引:1,自引:0,他引:1
应用外部电容耦合式等离子体聚合装置,研究了二甲基苯胺等离子体聚合规律,找到了最佳的聚合条件。通过热失重,红外光谱、X-射线衍射、电子衍射和接触角测定等,研究聚合物结构与性能。电导率测定表明二甲基苯胺等离子体聚合物具有半导体性质。 相似文献
3.
Solid-state polymerization has many advantages such as solvent-free, environmental friendly, less cost, and high purity of
product. In this study, a crystal film of polyacrylamide was synthesized by solid-state polymerization. Firstly, gelatin was
used for inducing acrylamide to form monomer crystal film through self-assembly in an aqueous solution. Then, the monomer
crystal film underwent a photo-initiating polymerization to give the corresponding polymer crystal film. The structure of
the crystal film was confirmed by Fourier-transformed infrared spectrometry, X-ray diffraction, microscopic melting point
detector, and differential scanning calorimeter. The morphology was observed with scanning electron microscopy. The molecular
weight was measured by gel permeation chromatography. It was found that a well-organized polyacrylamide crystal film was formed
by controlling the synthetic conditions. The lattice size of the crystal changed very little before and after polymerization.
The crystal film displayed a fibrous shape and was well-organized. 相似文献
4.
Shengjie Lan Donghai Zhu Li Dang Ziyang Huang Linbo Yang Ziyu Xu 《Surface and interface analysis : SIA》2019,51(13):1316-1324
The surface of magnesium oxysulfate (MOS) whiskers was treated through plasma polymerization to increase the compatibility between the MOS whiskers and a polymer matrix. Different plasma parameters were chosen to determine the most hydrophobic coating. The surface structure of the plasma-treated MOS whiskers was examined. The MOS whiskers retained their crystal structure after plasma treatment, as shown by X-ray powder diffraction (XRD) analyses. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy analyses revealed that a polymer sheath was formed on the surface of the MOS whiskers, and interfacial chemical bonds were generated between the polymer sheath and the MOS whiskers. The thin-layer polymer sheath was uniform around the entire surface of the MOS whiskers and exhibited a typical amorphous structure, as determined by transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED) analyses. The possible reaction mechanism on the surface of the MOS whiskers under plasma treatment was then proposed. Finally, the effect of surface treatment was evaluated by scanning electron microscopy (SEM), measurement of the contact angle and contact angle hysteresis, and torque rheometer. Results showed that plasma treatment could markedly increase the hydrophobicity of the MOS whiskers' surface, effectively reducing the agglomeration and improving the dispersibility of the MOS whiskers in the matrix, which results in the improved compatibility between the MOS whiskers and the polyvinyl matrix, as well as the processability of the composites. 相似文献
5.
6.
G. Galli M. Ragnoli M. Bertolucci C.K. Ober E.J. Kramer E. Chiellini 《Macromolecular Symposia》2004,218(1):303-312
The surface structure and surface energy properties of fluorinated 2-vinylcyclopropane copolymers were investigated. The copolymers were prepared by free radical ring opening polymerization of fluorinated 1 and non-fluorinated 2 2-vinylcyclopropanes. NEXAFS experiments proved that the film surface was ordered with the fluorinated side groups possessing a relatively high orientational order. Contact angle measurements with different interrogating liquids permitted the polymer surface tension to be estimated. These surfaces showed both hydrophobic and oleophobic character, consistent with a low surface energy. 相似文献
7.
Zinc oxide nanoparticles, with an average size of about 40 nm, were encapsulated by polystyrene using in situ emulsion polymerization in the presence of 3-methacryloxypropyltrimethoxysilane (MPTMS) as a coupling agent and polyoxyethylene nonylphenyl ether (OP-10) as a surfactant. Polymerization mechanism of nanocomposite latex was discussed. Transmission electron microscopy (TEM) proved the presence of ZnO nanoparticle appeared to be monodisperse in nanosize in polymer composite particles. ZnO/PS nanocomposites were characterized by Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results of FT-IR and XPS revealed that the surface of ZnO particle was successfully grafted by PS through the link of the coupling agent between ZnO and polymer. TGA and DSC results indicated an enhancement of thermal stability of composite materials compared with the pure polymer. SEM (scanning electron microscope) images showed a perfect dispersion of the ZnO particles in latex film. In addition, UV-visible absorption measurements demonstrated that the ZnO/PS composite coatings display a perfect performance of absorbing UV light. 相似文献
8.
Sutar DS Padma N Aswal DK Deshpande SK Gupta SK Yakhmi JV 《Journal of colloid and interface science》2007,313(1):353-358
Silicon substrates with (100) orientation were modified with amino-silane self-assembled monolayer (SAM) to provide amino (NH(2)) moieties at the substrate surface. Self-organization of polyaniline during chemical polymerization, on this modified surface, leads to the growth of highly oriented films at the substrate-polymer interface. The morphology studied using scanning electron microscopy and atomic force microscopy revealed the formation of polymer film with well faceted pyramidal crystallites. XPS and FTIR spectroscopy were used to analyze the chemical structure of the film. X-ray diffraction measurements show the crystalline nature of the polyaniline, whose lattice parameters are in agreement with the reported values. This study underlines the importance of a SAM in deciding the structure and morphology of the deposited polymer. 相似文献
9.
A crystal of N-vinylcarbazole was polymerized by redox catalyst (ammonium persulfite/sodium bisulfate) in a suspended state in water and poly (vinyl carbazole) was obtained. The polymerization proceeded rapidly above 40°C without an induction period in the solid state. The molecular weight of the polymer increased with decreasing catalyst concentration and raising temperature. ηsp/c of polymer was in the range 0.04–0.07 and it was lower than that obtained in radiation-induced solid-state polymerization. Observation of the partially polymerized crystal through a polarizing microscope showed that the polymerization proceeded from the surface of the monomer crystal and that birefringence was observed in the polymer layer. In X-ray diffraction studies it was found that the polymer was crystalline. 相似文献
10.
Ewa Andrzejewska Aleksander uk Jzef Garbarczyk 《Journal of polymer science. Part A, Polymer chemistry》1988,26(12):3151-3158
The solid-state 1,3,5-trithiane polymerization initiated by UV-irradiation was studied at various irradiation times and various polymerization temperatures. The conversion of monomer to polymer reaches limiting values (at longest) in about 30 min of reaction. The apparent activation energy of this process is somewhat higher than in the chemically initiated polymerization. Generated by UV, active centers, which initiate the polymerization, are stable. On the basis of X-ray diffraction studies it was found that the prepared polythiomethylene has a hexagonal structure and high degree of crystallinity. In the polymer investigated, a new additional crystal phase is formed, which is not stable. 相似文献
11.
12.
Csaba Janaky Balazs Endrodi Angela Hajdu Csaba Visy 《Journal of Solid State Electrochemistry》2010,14(2):339-346
In this study vitamin B12 covered magnetite nanoparticles have been incorporated into a conducting polypyrrole. This polymer
was electrochemically synthesized in the presence of the B12-coated magnetite. The adsorption of B12 was demonstrated by the
decrease in absorbance of the vitamin in the supernatant liquid after B12 has been in contact with magnetite sol overnight.
The composition of the layers was studied by the electrochemical quartz crystal microbalance technique during the polymerization.
The slope of the mass change–charge curves indicate the incorporation of 27 m/m% magnetite and 15 m/m% B12. The redox transformation
of the film in monomer- and nanoparticle-free solutions was also investigated by this method and the difference in the virtual
molar masses of the moving species was evidenced. The morphology and the composition of the layers were characterized by scanning
electron microscopy combined with energy dispersive X-ray microanalysis measurements, which latter proved the successful incorporation
of the magnetic and bio-active components. The electrochemical behavior of the films unambiguously showed the complex redox
activity of the composites and the current surplus were quantified by the redox capacity of the layers. These data show the
doubling of the redox capacity in case of the hybrid material compared to the neat polymer. The successful enrichment of B12
can be exploited in the recently evidenced redox mediation process performed by a PPy/B12 film. 相似文献
13.
Yan Wang Jingmei Xu Si-xue Cheng K. P. Pramoda Tai-shung Chung Suat Hong Goh 《Liquid crystals》2003,30(7):753-764
Using the thin film polymerization approach, we have studied the texture evolution when synthesizing a novel liquid crystalline polymer (LCP) system based on Sumikasuper® LCPs. The main monomers used were p-acetoxybenzoic acid (ABA), 4,4'-biphenol (BP), isophthalic acid (IA), phthalic acid (PA) and terephthalic acid (TA). Polarizing optical microscopy (POM), FTIR, X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to study the thin film polymerization process and characterize the products. The generation and evolution of liquid crystal phases were monitored; the results revealed that there exists a composition range for the monomers to react and form liquid crystal materials. The critical temperature for LC formation in ABA/BP/IA system decreased with increasing ABA content. FTIR results confirmed the formation of polymers. AFM investigation suggested a similar process of morphological change to that observed using POM. An increasing surface roughness of the thin films with the progress of polymerization was also obtained from AFM analysis. A nematic LC texture of the polymer system was suggested by XRD examination. Results obtained by replacing BP with acetylated BP, and by conducting polymerization using two-monomer systems, suggest that BP units are included in polymers obtained by the thin film polymerization method. 相似文献
14.
This research is conducted to make solid-state electrolyte based on natural polymers, as an alternative material for energy storage such as battery. Natural polymers as materials of solid state batteries have various benefits, such as unlimited abundance, biodegradable, unleakage, stable form, excellent process, and electrochemical stability, compare to the liquid ones. In this study, a solid state polymer electrolyte based on natural polymer such as chitosan was synthesized by incorporating various ion salts (Li, Cu, Ag) in the polymer matrix. The synthesis of solid-state electrolyte polymer was carried out by casting method to make a thin polymer film. Then the ionic (Li, Cu, Ag) doping with various implant dose will be applied to the thin polymer film matrix by ionic implantation technique. The implanted polymer electrolytes are then characterized their conductivities, micro structures, and crystal structures by high precision LCR, scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD), respectively. The measured of conductivities showed that thin film polymers after implanted with ionic Li, Cu or Ag were increased the conductivity, meanwhile elemental analisys by electron dispersive spectroscopy indicated that ionic implant to chitosan was success. The modification of chitosan polymer to become electrolyte polymer can be concluded. 相似文献
15.
Conductive films of gold were assembled on flexible polymer substrates such as Kapton and polyethylene using a solution-based process. The polymer substrates were modified by using argon plasma and subsequent coupling of silanes with amino- or mercapto- terminal groups. These modified surfaces were examined by X-ray photoelectron spectroscopy and contact angle measurements. Colloidal gold was assembled onto the silane-modified surface from solution. The gold particles are attached to the surface by covalent interactions with the thiol or amine group. Formation of a conductive film is achieved by increasing the coverage of gold by using a "seeding" method to increase the size of the attached gold particles. Field emission scanning electron microscopy was used to follow the growth of the film. The surface resistance of the films, measured using a four-point probe, was about 1 Omega/sq. 相似文献
16.
Using the thin film polymerization approach, we have studied the texture evolution when synthesizing a novel liquid crystalline polymer (LCP) system based on Sumikasuper® LCPs. The main monomers used were p-acetoxybenzoic acid (ABA), 4,4′-biphenol (BP), isophthalic acid (IA), phthalic acid (PA) and terephthalic acid (TA). Polarizing optical microscopy (POM), FTIR, X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to study the thin film polymerization process and characterize the products. The generation and evolution of liquid crystal phases were monitored; the results revealed that there exists a composition range for the monomers to react and form liquid crystal materials. The critical temperature for LC formation in ABA/BP/IA system decreased with increasing ABA content. FTIR results confirmed the formation of polymers. AFM investigation suggested a similar process of morphological change to that observed using POM. An increasing surface roughness of the thin films with the progress of polymerization was also obtained from AFM analysis. A nematic LC texture of the polymer system was suggested by XRD examination. Results obtained by replacing BP with acetylated BP, and by conducting polymerization using two-monomer systems, suggest that BP units are included in polymers obtained by the thin film polymerization method. 相似文献
17.
This paper investigates DC plasma polymerization kinetics by combining plasma parameters with film deposition rate in different conditions. The monomers hexamethyldisiloxane (HMDSO) and pyrrole were used. Both single and double Langmuir probes were used to measure the plasma parameters in pulsed power and continuous discharges. In order to avoid probe tip contamination, the probe was heated. Plasma density and electron temperature are reported. The electron current wave form is obtained in pulse power conditions. From the data, a plasma polymerization model is proposed. The conclusion is that the monomer molecules and free radicals adsorbed on the substrate surface react with activated sites produced by high energy ions bombarding the film, resulting in polymerization at the film surface. 相似文献
18.
Light-weight and high-strength materials have attracted considerable attention owing to their outstanding properties, such as weight-reducing, acoustic absorption, thermal insulation, shock and vibration damping. Diamond possesses specific stiffness and strength arising from its special crystal structure. In this work, inspired by the diamond crystal structure, hollow-tube nickel materials with the diamond structure were fabricated using a diamond structured polymer template based on the Stereo Lithography Appearance technology. The diamond structured template was coated with Ni-P by electroless plating. Finally, the template was removed by high temperature calcinations. The density of the hollow tube nickel materials is about 20 mg/cm3. The morphology and composition of the resultant materials were characterized by scanning electron microscope, energy-dispersive spectrometry, and X-ray diffraction. The results showed that the surface of the Ni film was uniform with the thickness of 4 μm.The mechanical property was also measured by stress and strain tester. The maximum compression stress can be reached to40.6 KPa. 相似文献
19.
N,N′-methylene bis-acrylamide crosslinked N-vinyl-2-pyrrolidone (NVPMBA) polymer was prepared via suspension polymerization technique and used as a polymeric support for the reduction of Cu(II) to Cu(I). It was observed that NVPMBA matrix facilitated the stabilization of Cu(I) particles. Furthermore, the copper supported polymer catalyst (CuNVPMBA) was characterized by Fourier transform infrared, X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray analysis, transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), inductively coupled plasma optical emission spectroscopy, and derivative thermogravimetry analysis. SEM showed that both the polymer and CuNVPMBA exhibit a spherical morphology. TEM revealed that copper nanoparticles formed on the polymer surface have an average particle size of 5.14 nm. XPS analysis confirmed the presence of Cu(I) and Cu(II) in the ratio 1:2. The copper content in CuNVPMBA was found to be 1.25 wt%. CuNVPMBA was found to be very effective in promoting the click reaction between terminal alkynes and azides in aqueous media in the absence of ascorbate or external base under mild conditions to form 1,2,3-triazoles in excellent yield with a copper loading as low as 0.2 mol%. The catalyst could be reused and recycled several times without significant loss of catalytic activity. 相似文献
20.
V. F. Holland 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(1):173-182
The morphology of some amide-hydrazide polymers of the type useful for high-modulus X-500 class fibers has been characterized by transmission electron microscopy of thin films crystallized from dilute solution. Selected area electron diffraction was used to characterize the crystallinity and crystal structure of the thin films and precipitated polymer. The films were cast from concentrated solutions and crystallized by heating the films. The results of these studies revealed several unique features relative to the crystal structure of the all-para polymers. Thin films of the crystallized polymer showed a distinctive crystalline texture—the molecular chains were found to be preferentially oriented parallel to the film plane and randomly oriented about an axis normal to the film plane. Electron diffraction measurements showed equatorial reflection maxima at tilt angles of = 30, ±48, and =59 when the films were tilted on an axis parallel to the film plane. From these results a tentative crystal unit cell and theoretical crystal density were determined: a = 8.5 [Agrave], b = 4.9 Å, c (chain axis) = 29.6 Å, p (density) =1.51 g/cc. The value a/b = 1.735, which is very near 31/2, implies essentially hexagonal packing of the chains. Crystallization from dilute solution revealed lamellar structures resembling “single crystals” in the electron microscope similar to those observed in other crystalline polymers. However, in contrast to these other polymers, these “crystals” are not likely to contain folded chains because of the very rigid nature of the all-para poiyamide-hydrazide. 相似文献