Influence of filler on the properties of compositions based on epoxy oligomer

The properties of composites based on epoxy oligomer (EDO) and woody ash (WA) have been explored. As a result of the studies, it was proved that WA addition doubles the impact viscosity of composition, increases the density up to 40%, the hardness of the composite gradually increases with an increase of WA content. A uniform distribution of WA particles in the matrix is obtained.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

Engineering and Technology Journal ◽

10.30684/etj.v38i7a.384 ◽

2020 ◽

Vol 38 (7A) ◽

pp. 960-966

Author(s):

Aseel M. Abdullah ◽

Hussein Jaber ◽

Hanaa A. Al-Kaisy

Keyword(s):

Impact Strength ◽

Wear Rate ◽

Flexural Modulus ◽

Matrix Material ◽

Weight Fraction ◽

Pure Pmma ◽

Calcination Process ◽

The Matrix ◽

The Impact ◽

Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

Optical, Structural, and Dielectric Properties of Composites Based on Thermoplastic Polymers of the Polyolefin and Polyurethane Type and BaTiO3 Nanoparticles

Materials ◽

10.3390/ma14040753 ◽

2021 ◽

Vol 14 (4) ◽

pp. 753

Author(s):

M. Baibarac ◽

A. Nila ◽

I. Smaranda ◽

M. Stroe ◽

L. Stingescu ◽

...

Keyword(s):

Crystallization Process ◽

Weight Ratio ◽

Thermoplastic Elastomers ◽

Visible Spectral Range ◽

X Ray Diffraction ◽

Thermoplastic Polymers ◽

The Matrix ◽

Free Films ◽

Batio3 Nanoparticles ◽

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.

The Interactions between Polyphenols and Microorganisms, Especially Gut Microbiota

Antioxidants ◽

10.3390/antiox10020188 ◽

2021 ◽

Vol 10 (2) ◽

pp. 188

Author(s):

Małgorzata Makarewicz ◽

Iwona Drożdż ◽

Tomasz Tarko ◽

Aleksandra Duda-Chodak

Keyword(s):

Intestinal Bacteria ◽

Research Data ◽

Bioactive Metabolites ◽

Human Organism ◽

Comprehensive Knowledge ◽

Bidirectional Relationship ◽

The Matrix ◽

Intestinal Pathogens ◽

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols’ impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole “microbiota” and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).

Reliability Assessment of a Multi-State HVDC System by Combining Markov and Matrix-Based Methods

Energies ◽

10.3390/en14113097 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3097

Author(s):

Roberto Benato ◽

Antonio Chiarelli ◽

Sebastian Dambone Sessa

Keyword(s):

Current System ◽

Estimation Method ◽

Reliability Estimation ◽

Voltage Source ◽

Voltage Source Converter ◽

Hvdc System ◽

Critical Elements ◽

The Matrix ◽

The purpose of this paper is to highlight that, in order to assess the availability of different HVDC cable transmission systems, a more detailed characterization of the cable management significantly affects the availability estimation since the cable represents one of the most critical elements of such systems. The analyzed case study consists of a multi-terminal direct current system based on both line commutated converter and voltage source converter technologies in different configurations, whose availability is computed for different transmitted power capacities. For these analyses, the matrix-based reliability estimation method is exploited together with the Monte Carlo approach and the Markov state space one. This paper shows how reliability analysis requires a deep knowledge of the real installation conditions. The impact of these conditions on the reliability evaluation and the involved benefits are also presented.

Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽

10.3390/ma13051242 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1242

Author(s):

Olga Mysiukiewicz ◽

Paulina Kosmela ◽

Mateusz Barczewski ◽

Aleksander Hejna

Keyword(s):

Mechanical Properties ◽

Melt Flow Index ◽

Tensile Tests ◽

Mechanical Analysis ◽

Flow Index ◽

Scanning Calorimetry ◽

Metal Composites ◽

Pre Treatment ◽

The Impact ◽

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.0706 ◽

2012 ◽

Vol 279 (1742) ◽

pp. 3520-3526 ◽

Cited By ~ 37

Author(s):

Brian Tilston Smith ◽

Amei Amei ◽

John Klicka

Keyword(s):

Bird Species ◽

Tropical Regions ◽

Isthmus Of Panama ◽

Species Pairs ◽

The Matrix ◽

High Species Richness ◽

The Rich ◽

The Tropics ◽

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

Toughening of Polypropylene-Ethylene Copolymer with Nanosized CaCO3 and Styrene-Butadiene-Styrene

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.121-123.1451 ◽

2007 ◽

Vol 121-123 ◽

pp. 1451-1454

Author(s):

Jian Feng Chen ◽

Guo Quan Wang ◽

Xiao Fei Zeng ◽

Hong Ying Zhao

Keyword(s):

Average Particle Size ◽

Average Particle ◽

Single Screw Extruder ◽

Roll Mill ◽

The Matrix ◽

Ethylene Copolymer ◽

Styrene Butadiene Styrene ◽

Styrene Butadiene ◽

The Impact ◽

Butadiene Styrene

Nanocomposites of nanosized-CaCO3/polypropylene-ethylene copolymer (PPE) and nanosized CaCO3/ PPE/ styrene-butadiene-styrene (SBS) were prepared by using two-roll mill and single screw extruder. The average particle size of nanosized CaCO3 was determined to be about 30 nm. By adding nanosized CaCO3 into PPE matrix, the toughness of the matrix improves significantly. At nanosized CaCO3 content of 12 phr (parts per hundred PPE resin by weight), the impact strength of CaCO3/PPE at room temperature reaches 61.6 KJ/m2, which is 3.02 times that of unfilled PPE matrix. In addition, the synergistic toughening effect of nanosized CaCO3 and SBS particles on PPE matrix was investigated.

The Influence of Ultrasonic Energy on Chemical Treatment of Surface Properties and the Properties of Composites Made of Luffa Cylindrical Fiber-Polyester Resin

Journal of Engineering Materials and Technology ◽

10.1115/1.2969251 ◽

2008 ◽

Vol 130 (4) ◽

Cited By ~ 9

Author(s):

E. Dilara Koçak

Keyword(s):

Composite Structure ◽

Polyester Resin ◽

Unsaturated Polyester ◽

Natural Fibers ◽

Morphological Characteristics ◽

Mechanical Tests ◽

Cylindrical Fiber ◽

The Matrix ◽

Mechanical Performances ◽

Producing composites from natural fibers is known to be common. These fibers benefit from their mechanical performances, low density, and their biodegradability. However, it is necessary for the fibers to form adhesion in the matrix. Therefore, it is necessary to apply a chemical process to the surface of the fibers. In this study, four different processes in conventional and ultrasonic energies were applied on luffa cylindrical fibers. At the end of the application, a composite structure was formed on the fibers that were obtained by using unsaturated polyester resin. The changes in the characteristics of the composite structure were recorded by mechanical tests, Fourier transform infrared, X-ray diffractometer, and their morphological characteristics by means of scanning electron microscopy. Considering all the results, formic acid and acetic acid process results were found to adequately modify the fiber surfaces.

Microstructure and Mechanical Properties of 14Cr-ODS Steels with Zr Addition

High Temperature Materials and Processes ◽

10.1515/htmp-2018-0067 ◽

2019 ◽

Vol 38 (2019) ◽

pp. 404-410 ◽

Cited By ~ 4

Author(s):

Weijuan Li ◽

Haijian Xu ◽

Xiaochun Sha ◽

Jingsong Meng ◽

Zhaodong Wang

Keyword(s):

Mechanical Properties ◽

Hot Isostatic Pressing ◽

Oxide Dispersion Strengthened ◽

Nominal Composition ◽

Ods Steel ◽

Zr Addition ◽

Microstructure And Mechanical Properties ◽

The Matrix ◽

Ods Steels ◽

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.

Principle of Strength Reinforcement in Filled Rubbers

Rubber Chemistry and Technology ◽

10.5254/1.3539147 ◽

1967 ◽

Vol 40 (5) ◽

pp. 1337-1363 ◽

Cited By ~ 55

Author(s):

A. E. Oberth

Keyword(s):

Particle Size ◽

Crosslink Density ◽

High Modulus ◽

Stress Concentrations ◽

Volume Increase ◽

The Matrix ◽

Filled Rubbers ◽

Filler Particles ◽

Tear Properties ◽

Abstract Effects of filler on mechanical properties of composites result from stress concentrations developed in the matrix and filler particles. Stress concentrations in filler particles relieve stress in the matrix which, under a given load, deforms less than it would in absence of filler. This accounts for high modulus as well as strength reinforcement in filled materials. Stress concentration in the matrix, decreasing with increasing content of filler, is responsible for internal tearing of composites. Magnitude of this internal tearing, which can be measured by volume increase of a specimen under strain, depends on many factors such as: shape of filler, orientation of filler particles, particle size, particle size distribution, nature of boundary layer between filler and matrix, crosslink density and tear properties of the matrix, as well as environmental pressure in the test. High dilatation results in low tensile strength of the composite and conversely if dilatation is suppressed maximum strength reinforcement is obtained.