Preparation and Properties of Nanocomposites Based on Poly(Vinyl acetate) and Montmorillonite Organized with Acrylic Acid

2011 ◽  
Vol 335-336 ◽  
pp. 3-11
Author(s):  
Jun Wang
Keyword(s):  
Acrylic Acid ◽  
Vinyl Acetate ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
Emulsion Copolymerization ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Ft Ir ◽  
Vinyl Group

The nanocomposites of poly(vinyl acetate)/montmorillonite (PVAc/MMT) were prepared using vinyl acetate and organically modified alkaline calcium base montmorillonite (MMT) by in situ emulsion copolymerization. The organic modification was acrylic acid including terminal reactive vinylic group. The samples were characterized using fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD). Thermal properties of the PVAc/MMT films were studied by thermogravimetric (TG) and differential scanning calorimetric (DSC). The FT-IR results indicated that the vinyl group on the surface of the vinyl MMT nanoparticles had been successfully copolymerized with vinyl acetate. The XRD results demonstrated that the MMT was exfoliated during polymerization. The exfoliated PVAc/MMT nanocomposites showed a lower glass transition temperature (Tg) and a worse thermal stability compared with the pure PVAc. However, bonding power of the nanocomposite latex of PVAc/MMT was improved due to the strong interaction between silica nanoparticles and polymer matrix via covalent bonds.

Structural Characterization of ZnO/AC Composite Prepared from Spent Catalyst of Vinyl Acetate Synthesis

2012 ◽  
Vol 518-523 ◽  
pp. 3483-3487
Author(s):  
Wen Wen Qu ◽  
Wen Jin ◽  
Jin Hui Peng ◽  
Shu Yang
Keyword(s):  
Thermal Treatment ◽  
Vinyl Acetate ◽  
Operating Conditions ◽  
Carbon Surface ◽  
X Ray Diffraction ◽  
Spent Catalyst ◽  
Activation Temperature ◽  
Vinyl Acetate Synthesis ◽  
Ft Ir ◽  
Co2 Flow

ZnO/AC composite was prepared from spent catalyst of vinyl acetate synthesis by using conventional thermal treatment under CO2 atmosphere. The final composite was obtained with the operating conditions of activation temperature of 950°C, activation time of 120min and the CO2 flow rate of 600ml/min. The structure and surface properties of the ZnO/AC composite were observed and characterized by scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and the UV diffuse reflectance spectra. It was found that the zinc acetate present in the spent catalyst is transformed to zinc oxide (ZnO) after thermal treatment. ZnO particles were well adhered and uniformly distributed onto the carbon surface, forming ZnO/AC composite. The thermal treatment of the spent catalyst gives rise to a material with excellent adsorptive and photocatalytic properties.

Preparation of Hydrophobic CaCO3-Wood Composite In Situ

2010 ◽  
Vol 113-116 ◽  
pp. 1712-1715
Author(s):  
Cheng Yu Wang ◽  
Chang Yu Liu ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Organic Substrate ◽  
Dodecanoic Acid ◽  
Wood Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Contact Angle Analysis ◽  
Double Diffusive

The preparation of hydrophobic CaCO3-wood composite through a double-diffusive method using dodecanoic acid as organic substrate is demonstrated. The product was characterized by the contact angle analysis, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The mechanical properties of the product were measured. The results show that the synthesized CaCO3 fills in the wood cell and covers the surface of wood. The CaCO3-wood composite is hydrophobic. The mechanical properties of wood composite have significantly increased.

scholarly journals “PdO vs. PtO”—The Influence of PGM Oxide Promotion of Co3O4 Spinel on Direct NO Decomposition Activity

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 62 ◽  
Author(s):  
Gunugunuri K. Reddy ◽  
Torin C. Peck ◽  
Charles A. Roberts
Keyword(s):  
Photoelectron Spectroscopy ◽  
No Decomposition ◽  
Single Element ◽  
X Ray Diffraction ◽  
X Ray ◽  
Promotional Effect ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Thermal Stability Of

Direct decomposition of NO into N2 and O2 (2NO→N2 + O2) is recognized as the “ideal” reaction for NOx removal because it needs no reductant. It was reported that the spinel Co3O4 is one of the most active single-element oxide catalysts for NO decomposition at higher reaction temperatures, however, activity remains low below 650 °C. The present study aims to investigate new promoters for Co3O4, specifically PdO vs. PtO. Interestingly, the PdO promoter effect on Co3O4 was much greater than the PtO effect, yielding a 4 times higher activity for direct NO decomposition at 650 °C. Also, Co3O4 catalysts with the PdO promoter exhibit higher selectivity to N2 compared to PtO/Co3O4 catalysts. Several characterization measurements, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), and in situ FT-IR, were performed to understand the effect of PdO vs. PtO on the properties of Co3O4. Structural and surface analysis measurements show that impregnation of PdO on Co3O4 leads to a greater ease of reduction of the catalysts and an increased thermal stability of surface adsorbed NOx species, which contribute to promotion of direct NO decomposition activity. In contrast, rather than remaining solely as a surface species, PtO enters the Co3O4 structure, and it promotes neither redox properties nor NO adsorption properties of Co3O4, resulting in a diminished promotional effect compared to PdO.

scholarly journals Fabrication of the Hierarchical HZSM-5 Membrane with Tunable Mesoporosity for Catalytic Cracking of n-Dodecane

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 155 ◽  
Author(s):  
Zhenheng Diao ◽  
Lushi Cheng ◽  
Xu Hou ◽  
Di Rong ◽  
Yanli Lu ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Swelling Agent ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Adsorption Desorption

Hierarchical HZSM-5 membranes were prepared on the inner wall of stainless steel tubes, using amphiphilic organosilane (TPOAC) and mesitylene (TMB) as a meso-porogen and a swelling agent, respectively. The mesoporosity of the HZSM-5 membranes were tailored via formulating the TPOAC/Tetraethylorthosilicate (TPOAC/TEOS) ratio and TMB/TPOAC ratio, in synthesis gel, and the prepared membranes were systematically characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption–desorption, N2 permeation, inductively coupled plasma (ICP), in situ fourier transform infrared (FT-IR), ammonia temperature-programmed desorption (NH3-TPD), etc. It was found that the increase of the TPOAC/TEOS ratio promoted a specific surface area and diffusivity of the HZSM-5 membranes, as well as decreased acidity; the increase of the TMB/TPOAC ratios led to an enlargement of the mesopore size and diffusivity of the membranes, but with constant acid properties. The catalytic performance of the prepared HZSM-5 membranes was tested using the catalytic cracking of supercritical n-dodecane (500 °C, 4 MPa) as a model reaction. The hierarchical membrane with the TPOAC/TEOS ratio of 0.1 and TMB/TPOAC ratio of 2, exhibited superior catalytic performances with the highest activity of up to 13% improvement and the lowest deactivation rate (nearly a half), compared with the microporous HZSM-5 membrane, due to the benefits of suitable acidity, together with enhanced diffusivity of n-dodecane and cracking products.

scholarly journals Enzymatic Degradation of Acrylic Acid-Grafted Poly(butylene succinate-co-terephthalate) Nanocomposites Fabricated Using Heat Pressing and Freeze-Drying Techniques

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 376 ◽  
Author(s):  
Sheng-Hsiang Lin ◽  
Hsiang-Ting Wang ◽  
Jie-Mao Wang ◽  
Tzong-Ming Wu
Keyword(s):  
Acrylic Acid ◽  
Freeze Drying ◽  
Crystallization Rate ◽  
X Ray Diffraction ◽  
Butylene Succinate ◽  
Covalent Bonds ◽  
Polymer Backbone ◽  
Transmission Electron ◽  
Degradation Rates ◽  
Organically Modified

Biodegradable acrylic acid-grafted poly(butylene succinate-co-terephthalate) (g-PBST)/organically modified layered zinc phenylphosphonate (m-PPZn) nanocomposites were effectively fabricated containing covalent bonds between the g-PBST and m-PPZn. The results of wide-angle X-ray diffraction and transmission electron microscopy revealed that the morphology of the g-PBST/m-PPZn nanocomposites contained a mixture of partially exfoliated or intercalated conformations. The isothermal crystallization behavior of the nanocomposites showed that the half-time for crystallization of 5 wt % g-PBST/m-PPZn nanocomposites was less than 1 wt % g-PBST/m-PPZn nanocomposites. This finding reveals that increasing the loading of m-PPZn can increase the crystallization rate of nanocomposites. Degradation tests of g-PBST/m-PPZn nanocomposites fabricated using the heat pressing and the freeze-drying process were performed by lipase from Pseudomonas sp. The degradation rates of g-PBST-50/m-PPZn nanocomposites were significantly lower than those of g-PBST-70/m-PPZn nanocomposites. The g-PBST-50 degraded more slowly due to the higher quantity of aromatic group and increased stiffness of the polymer backbone. The degradation rate of the freeze-drying specimens contained a more extremely porous conformation compared to those fabricated using the heat pressing process.

A Facile Synthesis of Poly(3-octylthiophene)-Titanium Dioxide Nanocomposite Particles in Supercritical CO2

2008 ◽  
Vol 8 (9) ◽  
pp. 4743-4746 ◽  
Author(s):  
Haldorai Yuvaraj ◽  
Min Hee Woo ◽  
Eun Ju Park ◽  
Yeong-Soon Gal ◽  
Kwon Taek Lim
Keyword(s):  
Titanium Dioxide ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Photoluminescence Quenching ◽  
Tem Analysis ◽  
Ir Studies ◽  
Transmission Electron ◽  
Ft Ir ◽  
Synthesized Materials

Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.

Synthesis and characterization of composite polysulfone membranes for desalination in nanofiltration technique

2010 ◽  
Vol 62 (11) ◽  
pp. 2655-2663 ◽  
Author(s):  
A. Akbari ◽  
M. Homayonfal ◽  
V. Jabbari
Keyword(s):  
Acrylic Acid ◽  
Polyacrylic Acid ◽  
Graft Polymerization ◽  
Irradiation Time ◽  
Polymerization Process ◽  
Synthesis And Characterization ◽  
Porous Support ◽  
Ft Ir

Composite nanofiltration (NF) membrane was developed polyacrylic acid (PAA) in situ UV graft polymerization process using ultrafiltration (UF) polysulfone (PSF) membrane as porous support. FT-IR spectra indicated that grafting was performed and it show peaks at 1,732 cm−1 and 3,396 cm−1 region for CO and OH starching bond of acrylic acid (AA) monomer, respectively. AFM microscopy showed the roughness of surface was reduced by increase of UV irradiation times. Effect of irradiation time on the grafting of acrylic acid (AA) in the same concentration was discussed. The salts rejection increase was accompanied with grafting of polysulfone (PSF) ultrafiltration (UF) membrane. The rejection of Na2SO4, MgSO4, NaCl and CaCl2 salts by PSF-grafted-PAA nanofiltration (NF) membrane was in 98, 60, 52 and 30% respectively, under 0.3 MPa.

scholarly journals Role of Zingiber Officinale Essential Oil- Chitosan Based Biopolymer Film For Bioactive Packaging

2021 ◽  
Author(s):  
Sawsan A. Al-Hilifi ◽  
Rawdah M. Al-Ali
Keyword(s):  
Essential Oil ◽  
Food Packaging ◽  
Fourier Transforms ◽  
Zingiber Officinale ◽  
Differential Scanning Calorimetric ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Biopolymer Film

Abstract The recent interest in bio-packing at field of food become trending in the development of antimicrobial coatings. The focus of this study was to assess the potential application of zingiber officinale essential oil (GEO) in chitosan films (CHf). The data indicated that there were significant differences(p < 0.05) in the chemical composition of the samples.Forty-seven active compounds of the essential oil were identified from the rhizomes of ginger, which were identified byGC-MS. Fourier transforms infrared spectra (FT-IR) confirmed that an interaction between the hydroxyl groups of the phenolic compounds of the essential oil and the amide groups of polymer matrix. As shown the appearance of peaks at wavenumbers 1639cm-1 and 1558cm-1 Furthermore, X-ray diffraction results suggested a lower crystallintiyin CHf due to GEO effect. Differential Scanning Calorimetric (DSC) analysis revealed that CHf possessed high thermal stability, especially when different concentrations of GEO added. The bioactive CHf showed distinct activity against both positive and negative gram bacteria. They are Staphylococcus aurous, Bacillus subtillis, Streptococcus Sp. Escherichia coli, Salmonella Sp. Pseudomonas erugiosa. This results provides a comprehensive insight on the importance of films incorporated with EOs of interest in food packaging.

scholarly journals Thermal and electrical properties of polyimide/PANI nanofiber composites prepared via in situ polymerization

2018 ◽  
Vol 36 (2) ◽  
pp. 283-287
Author(s):  
Aseel A. Kareem
Keyword(s):  
In Situ Polymerization ◽  
Composite Films ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Nanofiber Composite ◽  
X Ray ◽  
Thermal And Electrical Properties ◽  
Ft Ir ◽  
Thermal Stability Of

Abstract Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI nanofiber filler enhanced the activation energy of PI composites from 0.37 eV to 0.34 eV.

scholarly journals Synthesis and Characterization of New Polyimide/Organoclay Nanocomposites Containing Benzophenone Moieties in the Main Chain

2017 ◽  
Vol 57 (2) ◽  
Author(s):  
Khalil Faghihi ◽  
Mostafa Ashouri ◽  
Akram Feyzi
Keyword(s):  
Main Chain ◽  
In Situ Polymerization ◽  
Clay Content ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

<p>A series of nanocomposites consist of organic polyimide and organo-modified clay content varying from 0 to 5 wt%, were successfully prepared by in situ polymerization. Polyimide used as a matrix of nanocomposite was prepared through the reaction of 1,4-bis [4-aminophenoxy] butane (APB) and 3،3΄،4،4΄-benzophenone tetra carboxylic dianhydride (BTDA) in N,N-dimethylacetamide (DMAc). The resulting nanocomposite films were characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).</p>

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