Preparation and characterization of acrylic polymer titania hybrid. A study of organicinorganic interactions in hybrid materials by micro-hardness Vickers

2002 ◽  
Vol 726 ◽  
Author(s):  
Van Nhan Nguyen ◽  
François Xavier Perrin ◽  
Jean-Louis Vernet
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Polymer Chains ◽  
Segmental Motion ◽  
Acrylic Polymer ◽  
Titania Content ◽  
Mineral Constituent ◽  
Free Films

AbstractMetal-oxide ceramer films have been developed using an acrylic polymer bearing a low amount of methacrylic acid units (ca. 4%mol) as the organic phase with titanium tetrabutoxide as the inorganic sol-gel precursor. The characterisation of free films was realized by various experimental methods. The formation of COOTi bonds prevents large scale phase separation between the organic component and the mineral network. Mechanical properties of the hybrid films have been investigated through dynamic mechanical analysis. The influence of the titania content on the damping peak amplitude suggests that titania is molecularly dispersed in the polymer matrix and that it significantly hinders the segmental motion of the polymer chains. However, the low content in potential carboxylic crosslinking sites explains why the glass transition temperature remains relatively unchanged when titania content increases. Vickers microhardness measurements used in this study allowed us to understand the contribution of the inorganic part (phase TiO2) to the mechanical properties of the polymer. The creep of hybrids has been studied carrying out hardness measurements under various indentation times. The mineral constituent leads to an important increase of the hardness and limits, in a significant way, the creep of polymer.

scholarly journals A Thermo-Mechanical Analysis of Laser Hot Wire Additive Manufacturing of NAB

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1023
Author(s):  
Glenn W. Hatala ◽  
Qian Wang ◽  
Edward W. Reutzel ◽  
Charles R. Fisher ◽  
Jennifer K. Semple
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Large Scale ◽  
Mechanical Analysis ◽  
Simulation Software ◽  
Aluminum Bronze ◽  
Hot Wire ◽  
Temperature Dependent ◽  
Temperature Dependent Properties ◽  
The Impact

There is increased interest in using nickel aluminum bronze (NAB) alloys in large-scale directed energy deposition additive manufacturing (DEDAM) processes for maritime applications, but one challenge lies in the component distortion that results from residual stress generated during fabrication. This paper describes the development and evaluation of thermo-mechanical simulations for laser hot wire (LHW) DEDAM of NAB to predict part distortion. To account for the dearth of temperature-dependent properties for NAB C95800 in open literature and public databases, temperature-dependent material and mechanical properties for NAB C95800 were experimentally measured using test specimens fabricated with a variety of DEDAM processes. Autodesk’s Netfabb Local Simulation software, a commercial finite-element based AM solver, was employed but with its heat source model modified to accommodate LHW DEDAM’s oscillating laser path and additional energy input supplied by the preheated wire feedstock. Thermo-mechanical simulations were conducted using both the acquired temperature-dependent material and mechanical properties and the constant room-temperature properties to assess the impact on simulation accuracy. The usage of constant properties in the thermo-mechanical analysis resulted in significantly different predicted distortion compared to those using the temperature-dependent properties, at times even predicting substrate displacement in an opposite direction.

scholarly journals Phase Behavior and Thermo-Mechanical Properties of IF-WS2 Reinforced PP–PET Blend-Based Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2342
Author(s):  
Ding Chen ◽  
Santosh K. Tiwari ◽  
Zhiyuan Ma ◽  
Jiahao Wen ◽  
Song Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
High Performance ◽  
Large Scale ◽  
Chemical Vapor ◽  
Mechanical Analysis ◽  
Scale Production ◽  
Inorganic Fullerene ◽  
Materials Used

The industrial advancement of high-performance technologies directly depends on the thermo-mechanical properties of materials. Here we give an account of a facile approach for the bulk production of a polyethylene terephthalate (PET)/polypropylene (PP)-based nanocomposite blend with Inorganic Fullerene Tungsten Sulfide (IF-WS2) nanofiller using a single extruder. Nanofiller IF-WS2 was produced by the rotary chemical vapor deposition (RCVD) method. Subsequently, IF-WS2 nanoparticles were dispersed in PET and PP in different loadings to access impact and their dispersion behavior in polymer matrices. As-prepared blend nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic differential scanning (DSC), dynamic mechanical analysis (DMA), and X-ray diffraction (XRD). In this work, the tensile strength of the PP/PET matrix with 1% IF-WS2 increased by 31.8%, and the thermal stability of the sample PP/PET matrix with 2% increased by 18 °C. There was an extraordinary decrease in weight loss at elevated temperature for the nanocomposites in TGA analysis, which confirms the role of IF-WS2 on thermal stability versus plain nanocomposites. In addition, this method can also be used for the large-scale production of such materials used in high-temperature environments.

Dynamic Mechanical Analysis of Multi-Walled Carbon Nanotube/HDPE Composites

2008 ◽  
Vol 8 (8) ◽  
pp. 4008-4012 ◽  
Author(s):  
S. Kanagaraj ◽  
R. M. Guedes ◽  
Mónica S. A. Oliveira ◽  
José A. O. Simões
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Large Scale ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Shift Factor ◽  
Damping Factor ◽  
Dynamic Mechanical ◽  
Thermal Analyzer ◽  
Wlf Model

Since the discovery of carbon nanotubes (CNTs), their remarkable properties make them ideal candidates to reinforce in advanced composites. In this attempt, an enhancement of mechanical properties of high density polyethylene (HDPE) by adding 1 wt% of CNTs is studied using Dynamic mechanical and Thermal analyzer (DMTA). The chemically treated and functionalized CNTs were homogeneously dispersed with HDPE and the test samples were made using injection molding machine. Using DMTA, storage modulus (E′), loss modulus (E″) and damping factor (tan δ) of the sample under oscillating load were studied as a function of frequency of oscillation and temperatures. The storage modulus decreases with an increase of temperature and increases by adding CNTs in the composites where the reinforcing effect of CNT is confirmed. It is concluded that the large scale polymer relaxations in the composites are effectively restrained by the presence of CNTs and thus the mechanical properties of nanocomposites increase. The transition frequency of loss modulus is observed at 1 Hz. The loss modulus decreases with an increase of temperature at below 1 Hz but opposite trend was observed at above 1 Hz. The shift factor could be predicted from Williams-Landel-Ferry (WLF) model which has good agreement with experimental results.

Synthesis-Morphology-Mechanical Properties Relationships Of Polymer-Silica Nanocomposite Hybrid Materials

1999 ◽  
Vol 576 ◽  
Author(s):  
P. Hajji ◽  
L. David ◽  
J. F. Gerard ◽  
H. Kaddami ◽  
J. P. Pascault ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Resonance Spectroscopy ◽  
Silica Nanocomposites ◽  
X Ray Scattering ◽  
Transmission Electron

ABSTRACTTwo types of polymer-silica nanocomposites have been prepared by undergoing free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) either in the presence of HEMA-functionalized SiO2 nanoparticles (Type 1) or during the simultaneous in situ growing of the silica phase through the acid-catalyzed sol-gel polymerization of tetraethoxysilane (TEOS) (Type 2). Relationships between synthesis, morphology and mechanical properties are discussed mainly on the basis of solid state 29Si nuclear magnetic resonance spectroscopy (NMR), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and dynamic mechanical analysis (DMA).

Elastomer nanocomposites based on NBR/BR/nanoclay: morphology and mechanical properties

2013 ◽  
Vol 33 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Shohreh Tolooei ◽  
Ghasem Naderi ◽  
Shirin Shokoohi ◽  
Sedigheh Soltani
Keyword(s):  
Mechanical Properties ◽  
Polymer Chains ◽  
Butadiene Rubber ◽  
Cure Characteristics ◽  
Fluid Uptake ◽  
Roll Mill ◽  
Dispersion State ◽  
Cure Time ◽  
Diffraction Patterns ◽  
Nanoclay Content

Abstract Ternary elastomer nanocomposites based on acrylonitrile butadiene rubber (NBR), polybutadiene rubber (BR) and two types of nanoclay (Cloisite 15A and Cloisite 30B) were prepared using a laboratory scale two-roll mill. The effects of nanoclay composition on the cure characteristics, mechanical properties and morphology of NBR/BR (50/50) nanocomposite samples containing 3, 5, 7 and 10 wt% nanoclay were investigated. According to the cure characteristics both types of nanoclay caused a reduction in the scorch time and optimum cure time of the nanocomposite compound. X-ray diffraction patterns of all samples suggested the intercalation of polymer chains into the silicate layers. This was confirmed by transmission electron microscopy (TEM) micrographs. Dynamic mechanical thermal analysis (DMTA) was utilized to study the dispersion state of nanoclay within the elastomer blend matrix. The results showed the development of mechanical properties with the establishment of interactions between nanoclay and polymer chains. Antiknock and brake fluid uptake were also reduced with increasing the nanoclay content.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

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