Influences of filler dispersity in epoxy resin on the electrical and mechanical performances of embedded capacitance materials

2018 ◽  
Vol 29 (20) ◽  
pp. 17939-17947 ◽  
Author(s):  
Weikai Zheng ◽  
Hong Chen ◽  
Xu Zhou ◽  
Rui Liu ◽  
Gang Jian ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Mechanical Performances ◽  
Filler Dispersity ◽  
Embedded Capacitance

scholarly journals Effect of Gravel-sand Ratio on Physico-mechanical, Thermal and Macrostructural Properties of Micro Epoxy Polymer Concrete based on a Mixture of Alluvial-dune Sand

2020 ◽  
Vol 14 (1) ◽  
pp. 247-261
Author(s):  
Zineb Kerrida ◽  
Hichem Berkak ◽  
Zoubir Makhloufi ◽  
Madani Bederina ◽  
Ahmida Ferhat
Keyword(s):  
Thermal Conductivity ◽  
Water Absorption ◽  
Epoxy Resin ◽  
Epoxy Polymer ◽  
Polymer Concrete ◽  
Dune Sand ◽  
Optimal Values ◽  
Compressive And Flexural Strengths ◽  
Mechanical Performances ◽  
Crushed Limestone

Introduction: In the Polymer Concrete (PC) composites, aggregates are the most important constituent, which considerably affect their performance. The purpose of this experimental study is to examine the effect of Gravel-to-Sand (G/S) ratio on the physico-mechanical, thermal and microstructural properties of epoxy micro-polymer concrete made up of local aggregates. Materials & Methods: The Micro Epoxy Polymer Concrete (MEPC) studied consists of epoxy resin as a binder and a mixture of two types of sands (alluvial (0/0.63 mm) and dune (0/4 mm) sands), as well as crushed limestone gravel (3/8 mm). Six compositions were prepared with two epoxy resin contents (10% and 14% of the total weight of mixture) and three G/S ratios (0.25, 0.50 and 0.75). The studied properties are density, water absorption, compressive and flexural strengths, thermal conductivity, thermal diffusivity, specific heat and macrostructure. Results & Discussion: The obtained results show that the G/S ratio, as well as the epoxy resin content, has a significant influence on the properties of MEPC. In addition, 14% epoxy resin and the G/S ratio of 0.75 can be considered as optimal values, which lead to very interesting physico-mechanical performances (denser and less porous material, more resistant with almost similar thermal conductivity). Moreover, the density, the water absorption and the optical microscopic observation confirm that mixes containing 14% epoxy are more impermeable, compact and homogeneous than those containing 10% epoxy. Conclusion: Finally, it should be noted that the incorporation of aggregates being relatively coarse decreases the grains’ specific surface and reduces the porosity of the granular mix, which enable the epoxy product to completely cover the surface of mineral grains. A perfect covering of aggregate grains with a bender improves the adhesion between the aggregates and the polymer matrix.

scholarly journals An experimental study on damaged cementitious mortars repaired by glass/epoxy composite materials

2020 ◽  
Vol 15 (1) ◽  
pp. 113-128
Author(s):  
Chouaib Aribi ◽  
Aissa Bouaissi ◽  
Brahim Safi ◽  
Mohammed Saidi
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Bending Strength ◽  
Glass Fibers ◽  
Side Surface ◽  
Sem Images ◽  
Flexural Response ◽  
The Matrix ◽  
Mechanical Performances ◽  
The Impact

Abstract This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.

scholarly journals Thermal and Mechanical Characterization of an Aeronautical Graded Epoxy Resin Loaded with Hybrid Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1388
Author(s):  
Aldobenedetto Zotti ◽  
Simona Zuppolini ◽  
Anna Borriello ◽  
Mauro Zarrelli
Keyword(s):  
Thermal Stability ◽  
Epoxy Resin ◽  
Silica Nanoparticles ◽  
Mechanical Analysis ◽  
Critical Stress Intensity Factor ◽  
Hybrid Nanoparticles ◽  
Damage Resistance ◽  
Step Procedure ◽  
One Step ◽  
Mechanical Performances

Synthesized silica nanoparticles (SiO2) were coated with a thin polydopamine (PDA) shell by a modified one-step procedure leading to PDA coated silica nanoparticles (SiO2@PDA). Core-shell (CSNPs) characterization revealed 15 nm thickness of PDA shell surrounding the SiO2 core (~270 nm in diameter). Different weight percentages of CSNPs were employed as filler to enhance the final properties of an aeronautical epoxy resin (RTM6) commonly used as matrix to manufacture structural composites. RTM6/SiO2@PDA nanocomposites were experimentally characterized in terms of thermal stability and mechanical performances to assess the induced effects by the synthesized CSNPs on pristine matrix. Thermal stability was investigated by thermogravimetry and data were modelled by the Doyle model and Kissinger methods. An overall enhancement in thermal stability was achieved and clearly highlighted by modelling results. Dynamic Mechanical Analysis has revealed an improvement in the nanocomposite performances compared to the neat matrix, with an increase in the glassy (+9.5%) and rubbery moduli (+32%) as well as glass transition temperature (+10 °C). Fracture Toughness tests confirmed the positive effect in damage resistance compared to unloaded resin with an impressive variation in critical stress intensity factor (KIC) and critical strain energy (GIC) of about 60% and 138%, respectively, with the highest SiO2@PDA content.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

Surface Structure in Microtomed Sections Caused by Glass and Diamond Knives

1971 ◽  
Vol 29 ◽  
pp. 456-457
Author(s):  
J. Temple Black ◽  
William G. Boldosser
Keyword(s):  
Plastic Deformation ◽  
Epoxy Resin ◽  
Carbon Coating ◽  
Surface Damage ◽  
Body Angle ◽  
Normal Manner ◽  
Bottom Side ◽  
Cutting Direction ◽  
Made In ◽  
Diamond Knife

Ultramicrotomy produces plastic deformation in the surfaces of microtomed TEM specimens which can not generally be observed unless special preparations are made. In this study, a typical biological composite of tissue (infundibular thoracic attachment) infiltrated in the normal manner with an embedding epoxy resin (Epon 812 in a 60/40 mixture) was microtomed with glass and diamond knives, both with 45 degree body angle. Sectioning was done in Portor Blum Mt-2 and Mt-1 microtomes. Sections were collected on formvar coated grids so that both the top side and the bottom side of the sections could be examined. Sections were then placed in a vacuum evaporator and self-shadowed with carbon. Some were chromium shadowed at a 30 degree angle. The sections were then examined in a Phillips 300 TEM at 60kv.Carbon coating (C) or carbon coating with chrom shadowing (C-Ch) makes in effect, single stage replicas of the surfaces of the sections and thus allows the damage in the surfaces to be observable in the TEM. Figure 1 (see key to figures) shows the bottom side of a diamond knife section, carbon self-shadowed and chrom shadowed perpendicular to the cutting direction. Very fine knife marks and surface damage can be observed.

Sign in / Sign up

Export Citation Format

Share Document