scholarly journals The synthesis, structure and properties of polypropylene nanocomposites

2007 ◽  
Author(s):  
◽  
Vishnu Kribagaran Moodley
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Polymer Nanocomposites ◽  
Material Properties ◽  
Layered Silicate ◽  
Impact Testing ◽  
Transmission Electron ◽  
Low Weight ◽  
Scanning Electron

Polymer nanocomposites may be defined as structures that are formed by infusing layered-silicate clay into a thermosetting orthermoplastic polymer matrix. The nanocomposites are normally particle-filled polymers for which at least one dimension of the dispersed particles is in nanoscale. These clay-polymer nanocomposites have thus attracted great interest in industry and academia due to their exhibition of remarkable enhancements in material properties when compared to the virgin polymer or conventional micro and macro-composites. The present work describes the synthesis, mechanical properties and morphology of nano-phased polypropylene structures. The structures were manufactured by melt- blending low weight percentages of montmorillonite (MMT) nanoclays (0.5, 1, 2, 3, 5 wt. %) and polypropylene (PP) thermoplastic. Both virgin and infused polypropylene structures were then subjected to quasi-static tensile tests, flexural tests, micro-hardness tests, impact testing, compression testing, fracture toughness analysis, dynamic mechanical analysis, tribological testing. Scanning electron microscopy studies were then conducted to analyse the fracture surfaces of pristine PP and PP nanocomposite. X-ray diffraction studies were performed on closite 15A clay and polypropylene composites containing 0.5, 1, 2, 3 and 5 wt. % closite 15A nanoclay to confirm the formation of nanocomposites on the addition of organo clays. Transmission electron miscopy studies were then performed on the PP nanocomposites to determine the formation of intercalated, exfoliated or agglomerated nanoclay structures. Analysis of test data show that the mechanical properties increase with an increase in nanoclay loading up to a threshold of 2 wt. %, thereafter the material properties degrade. At low weight nanoclay loadings the enhancement of properties is attributed to the lower percolation points created by the high aspect ratio nanoclays. The increase in properties may also be attributed to the formation of intercalated and exfoliated nanocomposite structures formed at these loadings of clay. At higher weight loading, degradation in mechanical properties may be attributed to the formation of agglomerated clay tactoids. Results of XRD, transmission electron microscopy studies and scanning electron microscopy studies of the fractured surface of tensile specimens verify these hypotheses.

The Impact Properties of a Polyurethane Composite Filled with Clay

2011 ◽  
Vol 197-198 ◽  
pp. 1100-1103
Author(s):  
Jian Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Analysis ◽  
Impact Testing ◽  
Impact Properties ◽  
Polyurethane Composite ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

A polyurethane/clay (PU/clay) composite was synthesized. The microstructure of the composite was examined by scanning electron microscopy. The impact properties of the composite were characterized by impact testing. The study on the structure of the composite showed that clays could be dispersed in the polymer matrix well apart from a few of clusters. The results from mechanical analysis indicated that the impact properties of the composite were increased greatly in comparison with pure polyurethane. The investigation on the mechanical properties showed that the impact strength could be obviously increased by adding 20 wt% (by weight) clay to the matrix.

scholarly journals Study on Grain Refinement Mechanisms and Mechanical Properties of bi-Modal Ti-55511 Titanium Alloy during Hot Rolling

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3351 ◽  
Author(s):  
Wei Chen ◽  
Xiaoyong Zhang ◽  
YongCheng Lin ◽  
Kechao Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hot Rolling ◽  
Shear Bands ◽  
High Ductility ◽  
Α Phase ◽  
Transmission Electron ◽  
Scanning Electron

Multi-pass hot rolling was performed on bi-modal Ti-55511 alloy with 50% rolling reduction at 700 °C. Mechanical properties were evaluated by tensile test, and microstructure evolution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the Ti-55511 alloy with bi-modal microstructure exhibits good strength and high ductility (1102 MPa, 21.7%). Comparatively, after 50% hot rolling, an enhanced strength and decreased ductility were obtained. The refinement of α phases leads to the increased tensile strength, while the fragmentation of the equiaxed α phase results in a decreased ductility. The fragmentation process of equiaxed α phases followed the sequence of: elongation of α phases → formation of grooves and localized shear bands → the final fragmentation accomplished via deepening grooves.

scholarly journals Development of Flexible Polyurethane Nanostructured Biocomposite Foams Derived from Palm Olein-Based Polyol

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Srihanum Adnan ◽  
Tuan Noor Maznee Tuan Ismail ◽  
Norhayati Mohd Noor ◽  
Nik Siti Mariam Nek Mat Din ◽  
Nurul ‘Ain Hanzah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Palm Olein ◽  
Nanocomposite Foams ◽  
Transmission Electron ◽  
Flexible Polyurethane ◽  
Pu Foams ◽  
Scanning Electron

This study examined the effect of organoclay montmorillonite (OMMT) on the mechanical properties and morphology of flexible polyurethane/OMMT nanocomposite (PU/OMMT) foams prepared from petroleum- and palm olein-based polyols. Palm-based PU foams exhibited inferior mechanical strength as compared to neat petroleum PU foams. However, addition of OMMT significantly improved the foams strength of flexible polyurethane/OMMT nanocomposite foams prepared from palm olein-based polyol (PU bionanocomposite foam). The morphology analysed by scanning electron microscopy (SEM) showed that the cell size of the foam decreased with increasing OMMT content. PU bionanocomposite foam with 5 wt% of OMMT had the most improved tensile (63%) and tear (48%) strengths compared to its neat counterpart. Transmission electron microscopy (TEM) revealed the exfoliated structure of the respective foam. It was concluded that OMMT improved mechanical properties and morphology of PU foams.

Effects of Thermal Treatment on the Morphology and Properties of CSM/Poly(Urethane-Isocyanurate) Composites Formed by SRIM Process

2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Treatment Time ◽  
Microphase Separation ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Scanning Electron

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.

The Effect of Tungsten on the Nucleation and Growth of thin Aluminum Alloy Films

1993 ◽  
Vol 317 ◽  
Author(s):  
Bea CAO ◽  
N. David Theodore ◽  
Hank Shin ◽  
Peter Fejes ◽  
Les Hendrickson
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Nucleation And Growth ◽  
Growth Behavior ◽  
Aluminum Films ◽  
Surface Energies ◽  
Transmission Electron ◽  
Thin Aluminum ◽  
Scanning Electron

ABSTRACTA variety of alloying elements are currently being investigated for their effects on the mechanical properties and reliability of thin aluminum films. In the present study, scanning electron microscopy and transmission electron microscopy are used to study the nucleation and growth of Al-1.5wt%Cu and Al-1.5wt% Cu-0.2wt% W films. Differences in Microstructure, nucleation and growth behavior are observed and are explained in terms of changes in surface energies and atomic Mobilities.

The Microstructure and Tribological Behavior of Ti/a-C and Ti/a-C:H Films Prepared by Magnetron Sputtering

2013 ◽  
Vol 420 ◽  
pp. 123-128
Author(s):  
Chun Fu Hong ◽  
Jian Zhong Wang ◽  
Wei Yan ◽  
Ang Ding ◽  
Zhi Yong Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetron Sputtering ◽  
Tribological Behavior ◽  
Carbon Matrix ◽  
High Wear Resistance ◽  
Transmission Electron ◽  
Scanning Electron

This paper reports two films, Ti/a-C and Ti/a-C:H, prepared on the Ti-6Al-4V alloys by magnetron sputtering in PVD and CVD process, respectively. The morphology and microstructure were characterized by Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Both films show nanosized Ti clusters incorporated into the amorphous carbon matrix. Mechanical properties of the films were investigated by nanoindentation and ball-on-disk tribo-test. Ti/a-C film shows a hardness as high as 40.9 GPa, while that of Ti/a-C:H is 12.2 GPa. Both films show reduced friction and high wear resistance.

Characterization of Polypropylene Nanocomposite Structures

2006 ◽  
Vol 129 (1) ◽  
pp. 105-112 ◽  
Author(s):  
K. Kanny ◽  
V. K. Moodley
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Material Properties ◽  
Melt Blending ◽  
Transmission Electron ◽  
Low Weight ◽  
Static Tensile ◽  
Exfoliated Nanocomposite ◽  
Nanocomposite Structures

This study describes the synthesis, mechanical properties, and morphology of nanophased polypropylene structures. The structures were manufactured by melt-blending low weight percentages of montmorillonite nanoclays and polypropylene thermoplastic. Both virgin and infused polypropylene structures were then subjected to quasi-static tensile, flexural, hardness and impact tests. Analysis of test data show that the mechanical properties increase with an increase in nanoclay loading up to a threshold of 2wt.%; thereafter, the material properties degrade. At low weight nanoclay loadings the enhancement of properties is attributed to the lower percolation points created by the high aspect ratio nanoclays. The increase in properties may also be attributed to the formation of intercalated and exfoliated nanocomposite structures formed at these loadings of clay. At higher weight loading, degradation in mechanical properties may be attributed to the formation of agglomerated clay tactoids. Results of transmission electron microscopy studies and scanning electron microscopy studies of the fractured surface of tensile specimens verify these hypotheses.

scholarly journals FEATURES OF STRUCTURE FORMATION AND CHANGES IN THE MECHANICAL PROPERTIES OF CAST Al-Mg-Si-Mn ALLOY WITH THE ADDITION OF (Ti+Zr)

2015 ◽  
Vol 55 (4) ◽  
pp. 282 ◽  
Author(s):  
Oleksandr Trudonoshyn ◽  
Maxim Puchnin ◽  
Kostiantyn Mykhalenkov
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Ageing Time ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Scanning Electron

<p>The as-cast and heat-treated structure of permanent mould castings of AlMg<sub>5</sub>Si<sub>2</sub>Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg<sub>2</sub>Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.</p>

Microstructure and Mechanical Properties of Mg-9Al-6.5Ca-3Zn-0.6Mn-XNd Alloys Prepared by Spray Forming

2011 ◽  
Vol 117-119 ◽  
pp. 1447-1452
Author(s):  
Guo Wei Zhang ◽  
Zheng Chen ◽  
Wei Chen ◽  
Hai Ying Xin ◽  
Jing Zhai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Spray Forming ◽  
Protective Atmosphere ◽  
Forming Technology ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron ◽  
Scanning Electron

The Mg-9Al-3Zn-0.6Mn-xNd alloys, preformed with φ300mm size, has been prepared by spray forming technology under a protective atmosphere. The microstructure and mechanical properties have been investigated by XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and strengths tested mechine. As a result, the precipitate phases in the alloys were the finest when the Nd content was 1% compared the alloys with the Nd content were 2% and 3%, the size of precipitation phases are between 1-2um and there are phases like Mg2Ca，Al2Ca，and MgZn2in the alloys. After extrusion, recrystallization microstructures were found in the alloys. The tensile strengths are between 400-450MPa and the yield strengths are between 350-370MPa respectively as the differences content of Nd in the alloys after heat treatment.

Self-Assembly of Aligned Multi-Walled Carbon Nanotubes in Polypropylene-Coated Multi-Walled Carbon Nanotubes Composites

2013 ◽  
Vol 669 ◽  
pp. 55-62 ◽  
Author(s):  
Yi Na Xiong ◽  
Xiao Hua Chen ◽  
Qun Huang ◽  
Long Shan Xu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Self Assembly ◽  
Butyl Methacrylate ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Polypropylene (PP)-coated multi-walled carbon nanotubes (MWNTs) composite with MWNTs exceptional alignment dispersed and improved mechanical properties was prepared with maleic anhydride (MAH) as a compatibilizer and poly (butyl methacrylate) (PBMA) as a binding. Scanning electron microscopy (SEM) results showed that MWNTs within composite were aligned without aggregation and the oriented MWNTs were connected by matrix. High-resolution transmission electron microscopy (HRTEM) results demonstrated that the nanotubes were densely coated with a PP layer. Infrared spectroscopy (IR) results revealed that there was covalently linkage of MWNTs with PP via MAH. The interactions between MWNTs-PP and MWNTs-PBMA induced orientation of MWNTs. The improved mechanical properties of PP - coated MWNTs composite was also shown.

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