scholarly journals Thermomechanical Assessment of Plastic Deformation in Model Amorphous Polyamide/Clay Nanocomposites

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Kunal Tulsyan ◽  
Saurabh Toshniwal ◽  
Gowri Dorairaju ◽  
Daniel F. Schmidt ◽  
Emmanuelle Reynaud
Keyword(s):  
Plastic Deformation ◽  
Mechanical Energy ◽  
Tensile Modulus ◽  
Clay Content ◽  
Clay Nanocomposites ◽  
Polymer Microstructure ◽  
Work Of Deformation ◽  
Amorphous Character

In an effort to isolate the role of nanofiller independent of changes in polymer microstructure, we report the processing and characterization of model amorphous polyamide/clay nanocomposites. Analyses confirm fully amorphous character, no change inTgor thermal stability, and a partially exfoliated structure. The tensile modulus, yield stress, and failure stress increase with the clay content, both in dried and conditioned samples. In contrast, failure strain decreases with increasing clay content in conditioned samples but is independent of clay content in dried samples. Concurrently, the conversion of mechanical work to heat during plastic deformation was studied using infrared thermography, with the heat of deformation estimated based on these results and compared to the work of deformation. These results allow us to quantify changes in deformation mechanism and to conclude that the presence of clay enhances the conversion of mechanical energy to heat in these materials.

Mechanical Characterization of Nanoclay Reinforced Polypropylene Composites at High Temperature Subjected to Tensile Loads

2012 ◽  
Vol 488-489 ◽  
pp. 567-571 ◽  
Author(s):  
Reza Eslami Farsani ◽  
Ziba Hedayat Nasab ◽  
S. Mohammad Reza Khalili ◽  
Neda Soleimani
Keyword(s):  
High Temperature ◽  
Tensile Modulus ◽  
Clay Nanocomposites ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
Twin Screw ◽  
First Time ◽  
Compatibilizing Agent

In this paper, Polypropylene (PP) nanocomposites are prepared by melt mixing in a twin-screw extruder by injection molding. The role of compatibilizing agent is performed by maleic anhydride grafted polypropylene (PP-g-MA) between nanoclay and PP. The effect of nanoclay particles (1, 3, 5 wt %) on the PP composites is investigated for tensile test at high temperature for the first time. Mechanical behaviors of PP/clay nanocomposites at both room temperature (RT) and high temperature (HT) are investigated in terms of tensile properties. Addition of nanoclay showed a significant enhancement in stiffness of PP/clay nanocomposites. Nearly 36% and 157% increase in the tensile modulus at both RT and HT are observed, respectively. But, the increase in tensile strength is almost negligible.

On the Role of Characterization in the Design of Interfaces in Nanoscale Materials Technology

2004 ◽  
Vol 10 (3) ◽  
pp. 324-335 ◽  
Author(s):  
S.P. Ringer ◽  
K.R. Ratinac
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Turbine Rotor ◽  
Clay Nanocomposites ◽  
Multimodal Approach ◽  
Transmission Electron ◽  
Different Types ◽  
And Control

This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer–clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials.

Preparation and Characterization of Biodegradable and Compatible Ethylene Vinyl Acetate (EVA)/Thermoplastic Starch (TPS) Blend Nanocomposites

2009 ◽  
Vol 67 ◽  
pp. 185-189
Author(s):  
Vivek Patel
Keyword(s):  
Vinyl Acetate ◽  
Thermo Gravimetric Analysis ◽  
Tensile Modulus ◽  
Ethylene Vinyl Acetate ◽  
Thermoplastic Starch ◽  
Clay Nanocomposites ◽  
Gravimetric Analysis ◽  
Cloisite 30B ◽  
Blend Nanocomposites

Ethylene vinyl acetate (EVA)/thermoplastic starch (TPS) clay nanocomposites were prepared through melt intercalation technique using Haake Rheocord 9000 batch mixer with two different organically modified clays (Cloisite 30B & Cloisite 20A) at different weight percentages (1-7 wt %).The EVA/TPS ratio of 70: 30 was taken as optimum blend ratio as evidenced from the mechanical strength and chosen for the nanocomposites preparation in the presence of MA-g-PE as a compatibilizer. The maize starch was plasticized and gelatinized by adding glycerol and water in the ratio of 70:20:10.The blend nanocomposites have been examined by various techniques for characterization. Differential scanning calorimeter (DSC) result shows that the crystallization temperature of the nanocomposite blends is significantly lower than the base blend. Addition of 30 wt % of modified starch to make EVA/TPS blend; there is deterioration of impact strength, tensile strength, tensile modulus and elongation at break which was significantly increased after incorporation of small quantity (1-7 wt %) of nanoclay. Thermo gravimetric analysis (TGA) showed that the thermal stability of blend nanocomposites were better than those of EVA/TPS blend.

scholarly journals Two Spectroscopies as Main Source for Investigation of Polymer-Clay Materials

2021 ◽  
Author(s):  
Gustavo Morari do Nascimento
Keyword(s):  
Molecular Structure ◽  
Clay Nanocomposites ◽  
Spectroscopic Techniques ◽  
New Materials ◽  
Smectite Clays ◽  
Lamellar Materials ◽  
X Ray Absorption ◽  
Clay Materials

In the recent years the synthesis and characterization of nanomaterials has been one of the most efficacious way to produce new materials with improved or completely new properties. The polymer-clay nanocomposites are one of the most interesting nanomaterials with the possibility to create a myriad of new materials with many applications. Lamellar materials are classified as two-dimensional (2D), because there are formed by platelets piled up in one crystallographic direction, as the graphite and clays. The synthesis of controlled dimensional nanostructures as well as the characterization of the intrinsic and potentially peculiar properties of these nanostructures are central themes in nanoscience. The study of different nanostructures has great potential to test and understand fundamental concepts about the role of particle dimensionality on their physicochemical properties. Among the various materials studied in the literature, undoubtedly, polymer-clay materials, especially conducting polymers with smectite clays, such as montmorillonites (MMT) are of particular note. Our group have paid many efforts in the characterization of nanomaterials by using powerful spectroscopic techniques to study both the guest and host in case of inclusion compounds, nanofibers, carbon allotropes or many phases present in polymer-clay nanocomposites. There are two central questions that it was possible to address in this study: (i) the molecular structure of the polymer is drastically changed inside the interlayer cavity of clay and (ii) by using the appropriate synthetic or heating route is possible to change the molecular structure of the confined polymer. In the follow lines, it is briefly told the main aspects of resonance Raman and X-ray absorption spectroscopies in the study of polymer-clay nanocomposites.

Effect of clay loading on the structural and mechanical properties of organoclay/HDI-based thermoplastic polyurethane nanocomposites

e-Polymers ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Narges Taheri ◽  
Soheil Sayyahi
Keyword(s):  
High Performance ◽  
Thermoplastic Polyurethane ◽  
Tensile Modulus ◽  
Clay Content ◽  
Hexamethylene Diisocyanate ◽  
Oh Groups ◽  
Clay Concentration ◽  
Organically Modified ◽  
Polymerization Method

AbstractThermoplastic polyurethane/organically-modified montmorillonite (TPU/OMMT) nanocomposites were synthesized by the pre-polymer polymerization method using Cloisite® 30B organoclay, 1,6-hexamethylene diisocyanate (HDI), polycaprolactone diol (PCL diol, 2000 g/mol) and 1,4-butanediol (BDO). The hard segment content of the TPU was maintained at ~25.5% while the role of clay content was investigated at 1, 3 and 5 wt.% of clay concentration. The aim of this work was to obtain a high-performance polyurethane system while reaching a general microstructure-property relationship for TPU/OMMT nanocomposites. Clay exfoliation was achieved at 1 and 3 wt.% of clay loadings while some agglomerated clay sheets were observed in samples containing 5 wt.% OMMT. Significant hydrogen bonding occurred between the urethane linkages with unreacted -CH2CH2OH groups of the OMMT particles which resulted in strong matrix-filler interactions. Consequently, the values of tensile modulus were enhanced with clay content; namely a 177% improvement was observed for samples containing 5 wt.% OMMT. On the other hand, samples exhibited more thermoplastic behavior with the increase of clay content which resulted in lower deformability and lower values of tensile strength.

Preparation and Characterization of Environmental-Friendly Epoxy Resins/Clay Nanocomposites

2007 ◽  
Vol 119 ◽  
pp. 219-222
Author(s):  
Fan Long Jin ◽  
Mi Jeong Han ◽  
Jae Rock Lee ◽  
Soo Jin Park
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Castor Oil ◽  
Epoxy Resins ◽  
Clay Content ◽  
Interfacial Properties ◽  
Clay Nanocomposites ◽  
Environmental Friendly ◽  
Epoxidized Castor Oil

The environmental-compatible epoxy resins/clay nanocomposites were prepared by using epoxidized castor oil (ECO) and two ion-exchanged clays. The glass transition temperature (Tg) and mechanical interfacial properties of ECO/clay nanocomposites were investigated. As a result, the nanocomposites showed higher Tg than that of neat ECO. The mechanical interfacial properties of both the nanocomposites were significantly increased on increasing the clay content.

scholarly journals The justification of interaction of fruits with the rolling-in device of a combine-harvester for harvesting cucurbit crops

2021 ◽  
Vol 37 ◽  
pp. 00183
Author(s):  
Maxim Ulyanov ◽  
Vitaly Ceplyaev ◽  
Michael Shaprov ◽  
Nikolay Ayugin
Keyword(s):  
Plastic Deformation ◽  
Critical Speed ◽  
Spherical Segment ◽  
Plastic Work ◽  
Laboratory Installation ◽  
Combine Harvester ◽  
Experimental Values ◽  
Work Of Deformation ◽  
The Impact

The role of cucurbit crops in the life of man has been studied and presented. The process of interaction between the rolling-in device of a combine-harvester and a fruit, as well as the process of hitting water-melons into different surfaces, have been considered. The diagram of the distribution of velocities when the rolling-in device interacts with a fruit, as well as the area of expansion of plastic deformation as a result of the impact of a fruit, have been presented. The equation of work, which arises when a fruit hits into the rolling-in device, has been considered, the work being decomposed into plastic work of deformation and elastic work of deformation. The work of plastic deformation, which arises when fruits come into collision with a surface, is considered in more detail, the work being decomposed into plastic work of deformation in the volume, which is limited by a spherical segment and a cone. The absolute and allowable velocities after the impact have been theoretically determined and substantiated. The parameters of allowable velocities for the varieties "Crimson sweet" and "Kholodok" have been theoretically found and the confirmation of the theoretical analysis was carried out in experimental research, which was conducted on a laboratory installation for determining the critical speed of impact on fruits of cucurbit crops. The comparison of the theoretical and experimental values of the terminal velocities confirms the credibility of the research.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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