Novel flame retardant epoxy/clay nanocomposites prepared with a pre-ground phosphorus-containing organoclay

2008 ◽  
Vol 23 (6) ◽  
pp. 1618-1630 ◽  
Author(s):  
Y.W. Chen-Yang ◽  
W.S. Wang ◽  
J.C. Tang ◽  
Y.W. Wu ◽  
H.S. Chen
Keyword(s):  
Electron Microscopy ◽  
Surface Hardness ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Transmission Electron ◽  
Phosphorus Containing ◽  
Large Increment ◽  
Silicate Layers

A series of novel epoxy/clay nanocomposites (EPOCg-x) were prepared with a selected epoxy resin and x wt% of a mechanically ground phosphorus-containing organoclay (POCg). The results of x-ray diffraction (XRD), Fourier transform infrared, and field emission scanning electron microscopy measurements showed that POCg was size-reduced, and its silicate layers were disordered by the grinding process. The results of XRD and transmission electron microscopy of the nanocomposites suggested that the POCg particles were well-dispersed in the epoxy matrix with a combination of intercalation and destruction platelet structures. The as-prepared nanocomposites remained thermally stable above 376 °C. Furthermore, the storage modulus in the glass state, surface hardness, char residue, and limiting oxygen index (LOI) of the as-prepared nanocomposite were all significantly increased with increasing the POCg content. The large increment of LOI, 10 units higher than that of neat epoxy, indicated that an extraordinary enhancement on flame retardancy was obtained from EPOCg-5.

Modification of clays with styrenic ionic liquid by Synthesis of in-situ Polystyrene Nanocomposite

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Mohammad Galehassadi ◽  
Fatemeh Hosseinzadeh ◽  
Mehrdad Mahkam
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Transmission Electron ◽  
Insitu Polymerization ◽  
Thermal Stability Of

Abstract Nanocomposites of polystyrene (PS) was prepared with new styrenic ionic liquid, N-(4-vinyl benzyl)-(N,N-dimethylamino) pyridinium chloride[VBMAP], surfactants used as organic modifications for the clays. Sodium montmorillonite (Na-MMT) was successfully modified by [VBMAP] to become OMMT through cation exchange technique which is shown by the increase of basalspacing of clay by XRD. The composite material based on polystyrene and organo-modified montmorillonite (OMMT) was prepared by insitu polymerization and characterized. The morphology of the polymer/clay hybrids was evaluated by X-ray diffraction (XRD) ,transmission electron microscopy (TEM) and scanning electron microscopy (SEM), showing good overall dispersion of the clay. The thermal stability of the polymer/clay nanocomposites were enhanced, as evaluated by thermogravimetric analysis.

Study on the Preparation and Properties of EVA-G-PU/OMMT Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 247-250
Author(s):  
Yu Qing Zhang ◽  
Yu Xin He ◽  
Li Zhang ◽  
Jun Xian Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Clay Nanocomposites ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Thermal Stabilities ◽  
X Ray ◽  
Transmission Electron ◽  
New Type

A new type of EVA-g-PU/OMMT nanocomposites was synthesized through the method of chemical modification and melt intercalation. FTIR testing showed that the PU prepolymer was grafted on EVA main chains successfully. The structures of EVA-g-PU/OMMT nanocomposites were characterized by X-ray diffraction (XRD) and by high-resolution transmission electron microscopy (HRTEM). The enhanced storage modulus of EVA-g-PU/OMMT nanocomposites was characterized by dynamic mechanical analysis (DMA). The thermal stabilities of EVA/clay nanocomposites were also studied by thermal gravimetric analysis (TGA). Mechanical testing showed that the tensile strength and tear strength of EVA-g-PU/OMMT nanocomposites were far superior to pure EVA.

Preparation of Highly Exfoliated Epoxy/Clay Nanocomposites by the Method of Ultrasonication Dispersion-Microwave Cure

2011 ◽  
Vol 418-420 ◽  
pp. 670-673 ◽  
Author(s):  
Kun Yan Wang ◽  
Shi Yang Zhou ◽  
Zhen Jiang ◽  
Xiao Qing Zhu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microwave Energy ◽  
Basal Spacing ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Second Stage ◽  
Transmission Electron ◽  
Layered Clay

A new ultrasonication dispersion – microwave cure (UD-MC) method for preparing highly exfoliated layered epoxy/clay nanocomposites was developed. The process was divided into two consecutive stages. In the first stage, the epoxy and organoclay were mixed by high stirring and ultrasonication in the presence of acetone. In the second stage, the mixture of epoxy and organoclay was cured with microwave of 400W and postcured at 135°C. The microstructure of the nanocomposites was characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results indicated that the basal spacing of the organoclay particles in the epoxy/clay mixture was significantly enlarged, up to around 75Å afther the ultrasonic treatment. The layered clay was highly exfoliated under the microwave energy; and the basal spacing of nanolayers was more than 90Å.

The Preparation and Characterization of a Novolac Cured Epoxy-Clay Nanocomposites

2006 ◽  
Vol 939 ◽  
Author(s):  
Tsung-Yen Tsai ◽  
Shau-Tai Lu ◽  
Chih-Hung Li ◽  
Chin-Jei Huang ◽  
Li-Chun Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Benzalkonium Chloride ◽  
Barrier Properties ◽  
Layered Silicates ◽  
Clay Nanocomposites ◽  
Crosslinking Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTIntercalated or exfoliated nanocomposites were composed by the novolac cured epoxy and one of three different kinds of layered silicates, such as montmorillonite (PK-802), saponite (Semecton-SA) and nontronite (PK-805). The bi-functional modifiers (PI/BEN or MI/BEN) with different ratio, which contained one of the promoters (2-phenylimidazole, PI and 2-methylimidazole, MI) of epoxy and benzalkonium chloride (BEN), were intercalated into the gallery regions of pure clays at the same time and followed by a crosslinking reaction. The properties of novolac cured epoxy/clay nanocomposites were characterized by wild-angle X-ray diffraction (WAXRD), thermal analysis (TGA/DSC), coefficiency of thermal expansion (TMA), mechanical properties (DMA), and transmission electron microscopy (TEM). According to the measurement, these novolac cured epoxy-clay nanocomposites have shown the significant improvement in the thermal, mechanical and barrier properties.

Effect of the Compatibilizer on Clay Dispersion in Polypropylene/Clay Nanocomposites

2012 ◽  
Vol 622-623 ◽  
pp. 847-850
Author(s):  
Sedigheh Bagheri-Kazemabad ◽  
Alireza Khavandi ◽  
Daniel Fox ◽  
Yan Hui Chen ◽  
Hong Zhou Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
Rheological Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Dispersion State ◽  
Clay Layers ◽  
Better Than

Polypropylene (PP)/clay nanocomposites were prepared via a melt mixing technique. Two types of compatibilizers, namely poly (ethyleneco-octene) (EOC-g-MA) and polypropylene grafted maleic anhydride (PP-g-MA), were selected to facilitate the nanocomposite formation. X-ray diffraction and transmission electron microscopy in conjunction with rheological analysis were used for studying the dispersion state of clay layers in these nanocomposites. The results showed with the introduction of EOC-g-MA to PP/clay, clay was dispersed better than the presence of PP-g-MA.

scholarly journals Effects of Vinyltriethoxysilane and Maleic Anhydride Grafted Polypropylenes on the Morphological, Thermal, Rheological, and Mechanical Properties of Polypropylene/Clay Nanocomposites

Proceedings ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 6 ◽  
Author(s):  
Heriarivelo Risite ◽  
Hicham Abou Oualid ◽  
Khalil El Mabrouk
Keyword(s):  
Electron Microscopy ◽  
Maleic Anhydride ◽  
Clay Content ◽  
Melt Processing ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Interaction Forces ◽  
X Ray ◽  
Transmission Electron ◽  
Degree Of Reinforcement

The morphology and properties of polypropylene (PP)/organoclay nanocomposites prepared by melt processing were investigated with a special interest on the different effects of the use of different grafted PP as compatibilizers, i.e., maleic anhydride or silane-grafted species, PP-g-MA or PP-g-Si. When either PP-g-MA or PP-g-Si was added, better improvement of properties was achieved. The addition of PP-g-Si was found to increase the crystallization temperature upon the clay addition in comparison to PP-g-MA. Moreover, the PP-g-MA proved to be more efficient than PP-g-Si. The degree of reinforcement was found to be dependent on the interaction forces between the polymer matrix/clay, which resulted in intercalated/partial exfoliated structures for PP-g-Si while increasing clay content induced a change from exfoliated to intercalated using PP-g-MA, as revealed by transmission electron microscopy observations and X-ray diffraction analysis.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

The Effect of the Microstructure of Diffusion Barriers on the Palladium Activation for Electroless Copper Deposition

2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park
Keyword(s):  
Electron Microscopy ◽  
Diffusion Barriers ◽  
Copper Deposition ◽  
X Ray Diffraction ◽  
Plan View ◽  
X Ray ◽  
Transmission Electron ◽  
Electroless Copper ◽  
Sheet Resistance Measurement ◽  
Scanning Electron

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.

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