Effects of natural hard shell particles on physical, chemical, mechanical and thermal properties of composites

2021 ◽  
pp. 096739112110207
Author(s):  
Yahya Hışman Çelik ◽  
Kadir Serdar Çelik ◽  
Erol Kilickap
Keyword(s):  
Thermal Conductivity ◽  
Compression Strength ◽  
Low Cost ◽  
Matrix Material ◽  
Specific Weight ◽  
Mechanical And Thermal Properties ◽  
Environmental Friendliness ◽  
Pistachio Shell ◽  
Hard Shell ◽  
Powder Particles

Shelled herbal foods are widely consumed. The evaluation of the shells of these foods is important due to their features such as low cost, ease of recycling and environmental friendliness. In this study, hazelnut shell (HS), pistachio shell (PS), and apricot kernel shell (AKS) were brought to powder particles by grinding to dimensions of 300–425 µm. Some of the powder particles were converted into ash at 900°C. The amounts of cellulose, ash, humidity, and metal in these particles via chemical analyses were determined, while their structural properties via X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analyses. Composite materials were produced by adding 15 wt.% to the polyester matrix material from these powder particles and ashes. Compression strength, hardness, specific weight, and thermal conductivity of these composites were analyzed. The lowest and highest humidity, ash, cellulose, hemicellulose, and lignin ratios in powders showed differences depending on the type of powders. The amount of Sn and K in the HS, PS, and AKS powders were close to each other, while the amount of Ca, Na, Mg, Fe, Mn, Cu, Zn and Si was higher in AKS powder. The reinforcement adding to the polyester increased the compression strength, hardness, specific weight and thermal conductivity properties.

A Novel, Low-Cost C-C Composite Heat Sink Material

1996 ◽  
Vol 445 ◽  
Author(s):  
W. Kowbel ◽  
V. Chellappa ◽  
J.C. Withers
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Low Cost ◽  
Mechanical And Thermal Properties ◽  
New Class ◽  
Dielectric Coatings ◽  
Potential Applications ◽  
New Material ◽  
New Type ◽  
Composite Heat

AbstractRapid advances in high power electronics packaging require the development of new heat sink materials. Advanced composites designed to provide thermal expansion control as well as improved thermal conductivity have the potential to provide benefits in the removal of excess heat from electronic devices. Carbon-carbon (C-C) composits are under consideration for several military and space electronic applications including SEM-E electronic boxes. The high cost of C-C composits has greatly hindered their wide spread commercialization. A new manufacturing process has been developed to produce high thermal conductivity (over 400 W/mK) C-C composites at greatly reduced cost (less than $50/lb). This new material has potential applications as both a heat sink and a substrate. Dielectric coatings such as A1N and diamond were applied to this new type of heat sink material. Processing, as well as mechanical and thermal properties of this new class of heat sink material will be presented.

scholarly journals Improving Some Mechanical Properties and Thermal conductivity of PMMA Polymer by using Environmental Waste

2021 ◽  
pp. 2188-2196
Author(s):  
Tagreed M. Al-Saadi ◽  
Anaam W. Watan ◽  
Hanaa G. Attiya
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Environmental Problem ◽  
Matrix Material ◽  
Weight Fraction ◽  
Reinforcement Rate ◽  
Mechanical And Thermal Properties ◽  
The Matrix ◽  
Pmma Polymer ◽  
Composite Samples

This study was achieved to satisfy two goals, the first of which is to treat an environmental problem represented by the disposal of date seeds, and the second is the use of these wastes to improve some mechanical and thermal properties of poly methyl methacrylate PMMA through strengthening different proportions of the powder of date seeds. Particles of date seeds were used as a natural strengthening material for PMMA polymer, by mixing the matrix material (resin) with the hardener while still stirring continuously for a period of 10 min. After that, the samples of the reinforced material were prepared by adding the powder of date seeds, which is the reinforcing substance, with different percentages of weight fraction (0, 0.5, 1, 2, 3, 5 wt. %) and a grain size of <75 µm, while continuing to stir (10 min) for a second time. The composite samples were prepared by the Hand-Lay-up method and cut according to the standard ASTM. Thermal conductivity and some mechanical properties, such as impact strength, tensile strength, compressive strength, flexural strength, and hardness, were studied. An improvement was found in all properties at the reinforcement rate of 1-2 wt. %.

Syntactic Closed-cell Foams Based on Silicon Carbide

2004 ◽  
Vol 851 ◽  
Author(s):  
Engin Ozcivici ◽  
Raman P. Singh
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Low Cost ◽  
Processing Technique ◽  
Mechanical And Thermal Properties ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Closed Cell ◽  
Carbide Matrix ◽  
Silicon Carbide Matrix

ABSTRACTClosed cell foams were fabricated by incorporating two different grades of hollow alumino-silicate spheres (cenospheres) into a silicon carbide matrix. The silicon carbide matrix was formed by the pyrolysis of a preceramic polymer, and multiple polymer infiltration and pyrolysis (PIP) cycles were employed to minimize the open voids in the material. The physical, mechanical and thermal properties of the fabricated foams were characterized as functions of the number of reinfiltration cycles. The open- and closed-void volume fractions were determined by measurements of bulk and skeletal densities. Mechanical properties, including strength and modulus, were evaluated using four-point bend and compression tests. Finally, thermophysical (thermal conductivity) values of the material were determined using laser-flash technique. This processing technique results in closed-cell syntactic foams with low density (≤ 1.8g/cm3), reasonable mechanical strength (∼ 30 MPa) and very low thermal conductivity (≤ 1 W/m-K). In this manner, this process can be used for the low-cost and net-shape fabrication of closed-cell silicon carbide syntactic foams for high temperature applications.

scholarly journals Assessment of Mechanical and Thermal Properties of Hemp-Lime Mortar

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 882
Author(s):  
Eliana Parcesepe ◽  
Rosa Francesca De Masi ◽  
Carmine Lima ◽  
Gerardo Maria Mauro ◽  
Maria Rosaria Pecce ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Mechanical Performance ◽  
Low Cost ◽  
Natural Fibers ◽  
Specific Weight ◽  
Experimental Program ◽  
Mechanical And Thermal Properties ◽  
Lime Mortar ◽  
The Sustainable Development ◽  
Hemp Fibers

The use of renewable and natural materials characterized by the low environmental impact is nowadays a key issue for the sustainable development of the construction industry. For this reason, the interest for natural fibers, to be used as reinforcement in composites as an alternative to other fibers, is continuously growing. In this paper, the use of hemp for reinforcing lime mortar used as plaster is considered with a multidisciplinary approach, taking into consideration the structural and thermal performance. Natural fibers have several advantages compared to industrial ones, such as low cost, low environmental impact, biodegradability, renewable nature. Moreover, these can show remarkable mechanical performance in relation to specific weight, and sometimes, as in the case of hemp fibers, these can improve the thermal insulation capacity of the plaster. However, the experimental results on the mechanical features are still lacking, especially to assess their durability, and the variability of thermal parameters with the mechanical characteristics. Therefore, this paper proposes an experimental program, developed at Laboratory of Materials and Structures (LAMAS) of the University of Sannio (Italy), aimed at investigating the main mechanical properties (compression strength, flexural strength) of lime mortar reinforced by hemp fibers and subjected to various environmental exposures and aging processes. The characterization is completed with the measurement for the produced samples of the thermal conductivity by means of the standardized guarded hot plate technique.

Thermal conductivity of biomimetic leaf composite

2017 ◽  
Vol 52 (13) ◽  
pp. 1737-1746 ◽  
Author(s):  
G Liu ◽  
R Ghosh ◽  
D Mousanezhad ◽  
A Vaziri ◽  
H Nayeb-Hashemi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Composite Structures ◽  
Volume Fraction ◽  
Cell Structure ◽  
Matrix Material ◽  
Mechanical And Thermal Properties ◽  
Ceramic Fibers ◽  
Fiber Morphology ◽  
Fiber Volume

The venous morphology of a typical plant leaf affects its mechanical and thermal properties. Such a material could be considered as a fiber reinforced composite structure where the veins and the rest of the leaf are considered as two materials having highly contrast mechanical and thermal properties. The variegated venations found in nature is idealized into three principal fibers—the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. This paper addresses the in-plane thermal conductivity of such a composite by considering such a venous fiber morphology embedded in a matrix material. We have considered two cases, fibers having either higher or lower conductivity respect to the matrix. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element based computational investigation of the thermal conductivity of these composites under uniaxial thermal gradients and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find the heat conductivity in the direction of the main fiber (Y direction) increases significantly as the fiber angle of the secondary increases. Furthermore, for composite with metal fibers, the conductivity in the Y direction is further enhanced when composite is manufactured by having secondary fibers forming a closed cell structure. However, for composite with ceramic fibers, the conductivity of the composite in the Y direction is little affected by having secondary fibers closed. An opposite behavior is observed when considering conductivity of the composite in the X direction. The conductivity of the composite in the X direction is reduced with increase in the angle of the secondary fibers. Higher conductivity in the X direction is achieved for composite with no closed cells for composites with metal fibers. The results also indicate that for composites with the constant fiber volume fraction, morphology of tertiary fibers may not significantly alter material conductivities. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.

scholarly journals The Effect Of Phoenix Dactylifera L. Pinnae Reinforcement On The Mechanical And Thermal Properties Of Polymer Composite

2019 ◽  
Vol 25 (104) ◽  
pp. 339-351
Author(s):  
Adil I. Khadim ◽  
Dhefaf H.Badrri ◽  
Zainab S. Abdul-Ridha
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Fiber Length ◽  
Matrix Material ◽  
Phoenix Dactylifera ◽  
Mechanical And Thermal Properties ◽  
Green Leaves ◽  
Phoenix Dactylifera L ◽  
The Impact ◽  
Composite Samples

Phoenix  dactylifera l. pinnae (the green leaves of dates palm) were used as natural reinforcing (strengthening) fibers to improve the mechanical properties of polyester as a matrix material, the fibers of the green leaves of dates palm were used in two lengths, 10 and 20mm with five rates of 0, 2.5, 5, 10, and 20% , where the reinforcing with the leaves fibers increases the hardness strength from 76.5 to be about 86.55, the Impact value raised from about 0.313 to 0.461, in addition to that the flexural strength from 2.66 to be about 55, and the thermal conductivity increases from 2.54 ????∕????.℃ to 5.41 ????∕????.℃. The results of the present search explains that the composite samples reinforced at rate 20% and 10mm fiber length gives the best results.

Thermal, Strength and Leachability Characteristics of Cellulose Fibre Reinforced Lime-Soil Brick

2016 ◽  
Vol 703 ◽  
pp. 386-395 ◽  
Author(s):  
Weerapol Namboonruang ◽  
Prayoon Yongam-Nuai
Keyword(s):  
Thermal Conductivity ◽  
Flexural Strength ◽  
Low Cost ◽  
Extraction Procedure ◽  
Cellulose Fibre ◽  
Local Area ◽  
Mechanical And Thermal Properties ◽  
Natural Cellulose ◽  
Mechanical Performances ◽  
Masonry Units

This research studies on the possibility of producing a more sustainable lightweight brick. Natural cellulose fibre produced from leaf and wood aggregates, lime and soil from local area of Thailand were added into the brick with minimizing Portland cement content. Effects of varied amount of cellulose fibre contents typically (10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 %) on mechanical and thermal properties of bricks are studied. Mechanical performances have been investigated with compressive, flexural strength and thermal conductivity of the samples. Also, the Leachate Extraction Procedure is observed. Results showed that adding more cellulose fibre contents can reduce the thermal conductivity, density including the compressive and flexural strength of the brick. On the other hand, the water absorption increases. It is also shown that the composite bricks can add fibre contents up to 55% by weight that can be used as non-load bearing concrete masonry units considered by the compressive strength. By conclusion, this application may be an interesting solution in order to improve sustainability and energy efficiency of the low cost house in local area of Thailand.

scholarly journals little-known facts about silicate bricks and fires

2019 ◽  
Vol 138 ◽  
pp. 01009
Author(s):  
Alexandr Ibragimov
Keyword(s):  
Thermal Conductivity ◽  
Frost Resistance ◽  
Low Cost ◽  
High Strength ◽  
High Water ◽  
Historical Background ◽  
Technical Diagnostics ◽  
Color Gamut ◽  
Environmental Friendliness ◽  
Wide Color Gamut

The article presents a brief historical background about the epistemology of silicate brick. Well-known facts about silicate brick are given: the technological scheme of manufacture, modern grades for strength and frost resistance, information about thermal conductivity, classification by species, size and purpose. Advantages are considered, among which are noted: relatively low cost, environmental friendliness, compatibility with masonry mortars, aesthetics, wide color gamut, good geometric parameters, high strength characteristics, good soundproof ability, relatively high frost resistance, ease of processing. Disadvantages are given, among which are noted: high thermal conductivity, high water absorption, brittleness, and instability to acidic and alkaline aggressive environments. Particular attention is given to the consideration of the behavior of silicate brick and masonry from it in a fire. References to works devoted to this problem are given. The research of high temperature effects on the brickwork of the silicate bricks in the fire was held. A model for the possible collapse of brickwork as a re-sult of reducing its bearing ability due to fire was designed. The conclusion is drawn about the need for technical diagnostics of the structures of buildings made of silicate brick exposed to fire, as well as the special tactics of extinguishing fires in such buildings.

scholarly journals Low-Cost Jute-Cotton and Glass Fibre Reinforced Textile Composite Sheet

2020 ◽  
pp. 1-7 ◽  
Keyword(s):  
Glass Fibre ◽  
Low Cost ◽  
Matrix Material ◽  
Superior Performance ◽  
Engineering Properties ◽  
Mechanical And Thermal Properties ◽  
Textile Composite ◽  
Reinforced Composite ◽  
Single Structure ◽  
Glass Fibre Reinforced

Composite material is a single structure composed of two or more materials with identifiable interfaces at multi-scales to get properties that are superior to those of its constituents. Composites are designed to get unique mechanical properties and superior performance characteristics that are not possible with any of its component material alone. An experimental work was done at Textile Physics Division of BJRI, Bangladesh, in 2019 for the manufacture of jute, cotton and glass fire reinforced composite corrugated sheet suitable for roofing in poultry and rural housing. For the investigation jute, cotton and glass fibre were used like as reinforcing material and polyester resin were used like as matrix material. This paper reports the findings of an experimental investigation conducted on the engineering properties of jute, cotton and glass fibre reinforced composite corrugated sheet. Different fabric design and volume fractions were used as reinforcement for corrugated sheet to determine the physical, mechanical and thermal properties of the composite. The results of this investigation have shown the feasibility of the use of jute fibre for producing low-cost housing materials.

scholarly journals A review of biomass materials for advanced lithium–sulfur batteries

2019 ◽  
Vol 10 (32) ◽  
pp. 7484-7495 ◽  
Author(s):  
Huadong Yuan ◽  
Tiefeng Liu ◽  
Yujing Liu ◽  
Jianwei Nai ◽  
Yao Wang ◽  
...  
Keyword(s):  
Recent Progress ◽  
Low Cost ◽  
High Abundance ◽  
Chemical Adsorption ◽  
Environmental Friendliness ◽  
Lithium Sulfur Batteries ◽  
Biomass Materials ◽  
Physical And Chemical ◽  
Lithium Sulfur

This review summarizes recent progress of biomass-derived materials in Li–S batteries. These materials are promising due to their advantages including strong physical and chemical adsorption, high abundance, low cost, and environmental friendliness.

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