scholarly journals Morphology Evolution and Rheological Behaviors of PP/SR Thermoplastic Vulcanizate

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 175 ◽  
Author(s):  
Qiang Wu ◽  
Jiafeng Fang ◽  
Minghuan Zheng ◽  
Yan Luo ◽  
Xu Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Complex Viscosity ◽  
Mechanical Analysis ◽  
Dynamic Strain ◽  
Hot Press ◽  
Dynamic Vulcanization ◽  
Shear Rates ◽  
High Shear Rates ◽  
Transmission Electron ◽  
Rubber Aggregates

The thermoplastic vulcanizates (TPVs) of polypropylene (PP)/silicone rubber (SR) were prepared by dynamic vulcanization (DV) technology. The mixing torque, morphology, viscoelasticity, and creep response of PP/SR TPVs were investigated by torque rheometer, scanning electron microscope (SEM), transmission electron microscope (TEM), rotational rheometer, and dynamic mechanical analysis (DMA). A mixing-torque study showed that torque change and dynamic-vulcanization time increased with SR content increasing in the DV process, but DV rate was independent of SR content. TEM images indicated that the phase inversion of PP/SR-60 TPV from bicontinuous to a sea–island structure took place in the DV process, and a hot press would break the rubber aggregates and shrink a large SR phase. Dynamic-strain measurement demonstrated that PP/SR TPVs exhibit a distinct “Payne effect”, which can be attributed to the destruction and reconstruction of SR physical networks. Complex viscosity indicated that SR content did not affect the processability of PP/SR TPVs at high shear rates. Furthermore, the creep deformation and recovery of PP/SR TPVs at solid and melt states were studied, respectively.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

scholarly journals Morphology, Dynamical Mechanical and Flame Retardant Properties of Nylon 1212/Organic Montmorillonite Nanocomposites Prepared by Melt Compounding

2021 ◽  
Vol 5 (2) ◽  
pp. 11-17
Author(s):  
Anrong Huang ◽  
Jing Sun ◽  
Shanshan Luo ◽  
Heng Luo
Keyword(s):  
Electron Microscope ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Mechanical Analysis ◽  
Cone Calorimetry ◽  
X Ray ◽  
Organic Montmorillonite ◽  
Melt Compounding ◽  
Transmission Electron ◽  
Flame Retardant Properties

Nylon 1212/organic montmorillonite (OMMT) nanocomposites were prepared using the melt compounding method. The morphology and dynamical mechanical properties of the nanocomposites were investigated using transmission electron microscope (TEM) and dynamic mechanical analysis (DMA). The storage modulus of nylon 1212/OMMT nanocomposites was increased with increasing OMMT. The flame retardant properties were characterized by cone calorimetry, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The flame retardant properties were characterized using cone calorimetry, whereby nylon 1212/OMMT nanocomposites were improved compared with pure nylon 1212 because of the carbonaceous-silicate granular materials which were formed during combustion, thus proposing the flame retardant mechanism.

scholarly journals Water-Jet Erosion of Grade-A Ship Steel: Experimental Research

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yupeng Cao ◽  
Yue Zhang ◽  
Weidong Shi ◽  
Hua Lu ◽  
Linwei Tan ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Central Area ◽  
Water Jet ◽  
Dynamic Strain ◽  
Material Surface ◽  
Transmission Electron ◽  
Peripheral Area ◽  
Erosion Test ◽  
The Impact ◽  
Strain Signal

A water-jet erosion test was carried out on grade-A ship steel to study the interaction and erosion mechanism of the water jet on the steel surface. When the water jet impacted, a STSS-1 stress-detection module was used to collect the dynamic strain signal on the rear of the ship’s plate, and a scanning electron microscope, transmission electron microscope, X-ray diffractometer, and other equipment were used to analyze the microstructure and phase of the grade-A ship steel before impact. The surface morphology of the material after impact was studied and analyzed. The impact stress of the water jet on the grade-A steel was an alternating stress, and the jet pressure decayed in the radial direction. The material surface was fatigued under the action of the jet alternating stress. After the water-jet erosion, the central area of the grade-A steel was dominated by an elongated cementite hard phase, and the peripheral area had a pearlite structure. A model for the jet erosion and peeling of grade-A ship steel was established to clarify the mechanism of erosion by the water jet.

Influence of Maleation of Ground Rubber Tyre (GRT) on the Thermorheological behaviour of Thermoplastic Elastomers Based on Ethylene Propylene Diene Rubber, GRT and Ethylene-co-acrylic acid

2002 ◽  
Vol 10 (6) ◽  
pp. 427-432 ◽  
Author(s):  
Amit K. Naskar ◽  
S. K. De ◽  
Anil K. Bhowmick
Keyword(s):  
Mechanical Analysis ◽  
Thermoplastic Elastomers ◽  
Capillary Rheometer ◽  
Melt Fracture ◽  
Shear Rates ◽  
Ground Rubber ◽  
High Shear Rates ◽  
The Matrix ◽  
Diene Rubber ◽  
Low Shear

The thermorheological behaviour of thermoplastic elastomeric blends based on both ground rubber tyre (GRT) and maleic anhydride grafted GRT (m-GRT) has been studied. The blend composition based on m-GRT exhibits a higher melt viscosity than the corresponding control blend based on GRT. The former exhibits lower die swell and less melt fracture at low shear rates than the latter, when extruded at 180°C through a capillary rheometer. At high shear rates, however, both the blends exhibit melt fracture. There is apparently some interaction between m-GRT and the matrix, which is evident from dynamic mechanical analysis. The m-GRT causes a significant lowering in tanδ at temperatures higher than the Tg of the blend.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Surface Structure of the Spores of Glugea Weissenbergi

1969 ◽  
Vol 27 ◽  
pp. 238-239
Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague
Keyword(s):  
Electron Microscope ◽  
Surface Structure ◽  
Transmission Electron Microscope ◽  
Mature Spore ◽  
Spore Surface ◽  
Sectioned Material ◽  
Transmission Electron ◽  
Surface Detail

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

S.E.M.-T.E.M. Image Comparison

1971 ◽  
Vol 29 ◽  
pp. 132-133
Author(s):  
G. M. Greene ◽  
J. W. Sprys
Keyword(s):  
Electron Microscope ◽  
Low Carbon Steel ◽  
Secondary Emission ◽  
Low Carbon ◽  
Preparation Time ◽  
Actual Surface ◽  
Fine Detail ◽  
Transmission Electron ◽  
Transmission Study ◽  
Large Sections

The present study demonstrates that fracture surfaces appear strikingly different when observed in the transmission electron microscope by replication and in the scanning electron microscope by backscattering and secondary emission. It is important to know what form these differences take because of the limitations of each instrument. Replication is useful for study of surfaces too large for insertion into the S.E.M. and for resolution of fine detail at high magnification with the T.E.M. Scanning microscopy reduces sample preparation time and allows large sections of the actual surface to be viewed.In the present investigation various modes of the S.E.M. along with the transmission mode in the T.E.M. were used to study one area of a fatigue surface of a low carbon steel. Following transmission study of a platinum carbon replica in the T.E.M. and S.E.M. the replica was coated with a gold layer approximately 200A° in thickness to improve electron emission.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

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