scholarly journals THERMAL AND MECHANICAL PROPERTIES OF BIOCOMPOSITES BASED ON GREEN PE-HD AND HEMP FIBERS

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Silvester Bolka ◽  
Janez Slapnik ◽  
Rebeka Rudolf ◽  
Rajko Bobovnik ◽  
Maja Mešl
Keyword(s):  
Thermal Stability ◽  
Mechanical And Thermal Properties ◽  
The Novel ◽  
Hemp Fiber ◽  
Bending Tests ◽  
Hemp Fibers ◽  
Two Factors ◽  
The Matrix ◽  
Dynamic Calorimetry ◽  
Full Factorial

Biocomposites of hemp fiber reinforced bio-based high density polyethylene (green PE-HD) were prepared using a maleic anhydride grafted styrene–ethylene/butylene–styrene (SEBS-g-MA) as a compatibilizer. Several compositions of biocomposites were prepared on a tween screw extruder using the full factorial design varying two factors with two levels. The mechanical and thermal properties of test specimens, prepared by injection molding, were investigated by tensile and bending tests, DMA, and ultra-fast differential dynamic calorimetry (Flash DSC). High stiffness and strength of biocomposites in comparison to neat green PE-HD indicate very good compatibility of the constituents. Stiffness of the samples without SEBS-g-MA is slightly higher than that of the samples with SEBS-g-MA. The thermal stability of biocomposites is for all samples drastically higher as compared to neat green PE-HD. The melting (Tm) and crystallization (Tc) temperatures of the biocomposites are shifted to higher temperatures. Incorporation of SEBS-g-MA together with hemp fiber into the matrix enhances strength, stiffness, impact strength and rises thermal stability. The novel biocomposites are suitable for applications such as technical parts, which require higher stiffness and thermal stability as compared to neat green PE-HD.

scholarly journals Hemp Fiber Reinforced Red Mud/Fly Ash Geopolymer Composite Materials: Effect of Fiber Content on Mechanical Strength

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 511 ◽  
Author(s):  
Eyerusalem A. Taye ◽  
Judith A. Roether ◽  
Dirk W. Schubert ◽  
Daniel T. Redda ◽  
Aldo R. Boccaccini
Keyword(s):  
Fly Ash ◽  
Mechanical Strength ◽  
Red Mud ◽  
Fiber Reinforced ◽  
Brazilian Tensile Strength ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Geopolymer Composites ◽  
Scanning Electron

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.

On an Original Approach to Model Hemp Fibers Reinforced Thermoplastics

2014 ◽  
Vol 875-877 ◽  
pp. 801-806
Author(s):  
Florian Gehring ◽  
Vanessa Bouchart ◽  
Florence Dinzart ◽  
Pierre Chevrier
Keyword(s):  
Behavior Modeling ◽  
Matrix Cracking ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Reinforced Thermoplastics ◽  
Modeling Strategy ◽  
Original Approach

This paper is devoted to present an approach to model behavior of hemp fibers reinforced thermoplastic composites. Experimental investigations using common testing methods have shown that major physical dissipative phenomena which explained the behavior of polypropylene/ hemp fibers (PP/Hemp) composites took place in the matrix. Moreover these dissipative mechanisms are mainly due to matrix cracking. The behavior modeling of PP/hemp fiber composites is obtained by a two-step modeling strategy. A real based microstructure is automatic generated by own made algorithms according to the observed microstructure by X-ray tomography and constitutive behavior of the matrix is obtained using the micromechanics formalism and is implemented by a FORTRAN routine in ABAQUS® software. This approach seems to have the potential to describe behavior of such composites (PP/Hemp).

scholarly journals Effects of different retting methods on thermal stability and mechanical properties of hemp fibers

2013 ◽  
Vol 17 (5) ◽  
pp. 1538-1541 ◽  
Author(s):  
Hong-Qin Yu ◽  
Shou-Hui Chen ◽  
Chong-Wen Yuc ◽  
Yan-Li Chang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Gum Content

Different retting methods were employed in hemp retting, treated hemp fibers by various retting methods were characterized by residual gum content, fineness, tenacity, elongation, and thermal gravimetric analysis. The results indicated that alkali-oxygen one bath process was satisfactory, which achieved hemp fiber with 2.14 tex, residual gum content 2.99% and tenacity 54.33 cN/tex.

Combination of silk fabric and natural rubber for the development of green composites: Influence of curing on mechanical and thermal properties

2021 ◽  
pp. 096739112110491
Author(s):  
Thanuj Kumar M ◽  
Sanga Shetty S G ◽  
Ekwipoo Kalkornsurapranee ◽  
Ladawan Songtipya ◽  
Yeampon Nakaramontri ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Tensile Properties ◽  
Mechanical And Thermal Properties ◽  
Relaxation Techniques ◽  
Silk Fabric ◽  
The Matrix ◽  
The Stability

Unmodified natural rubber is not suitable for any elstomeric applications. Therefore, it is appropriate to modify natural rubber chemically to enhance the stability, which can be termed as vulcanization. Incorporation of fibers/fabrics is a common method to increase the stability of natural rubber along with chemical modification. Natural rubber-based composites have been prepared by the addition of silk fabric into natural rubber. The matrix material for the composite is glutaraldehyde cured natural rubber. Silk is an ecofriendly and biodegradable material with excellent tensile strength. When such kind of fabric is introduced into the vulcanized rubber as the matrix, all the physical properties were found to be enhanced considerably. Tensile properties in terms of ultimate tensile strength, elongation at break, and modulus of elasticity are measured for the composites of natural rubber/silk fabric at various glutaraldehyde concentrations. Thermogravimetric analysis and temperature scanning stress relaxation techniques are employed to evaluate the thermal stability of the resulting composites. Effects of glutaraldehyde addition on the physical properties of the composite were studied in detail. Considerable enhancement in the stability of natural rubber in terms of tensile properties, thermal stability, and solvent resistance is noticed up on the incorporation of silk fabric as well as glutaraldehyde curing.

Optimization and characterization of flavonoids extracted from Cannabis sativa fibers

2021 ◽  
pp. 004051752110277
Author(s):  
Qilu Cui ◽  
Jiawei Li ◽  
Chongwen Yu
Keyword(s):  
Chemical Structure ◽  
Cannabis Sativa ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Test Results ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Structure Surface ◽  
Degumming Process

In this paper, the extraction process of flavonoids from hemp fibers was studied. Response surface methodology (RSM) analysis of the extraction parameters indicated that optimized results would be ethanol concentration 76 vol.%, bath ratio 1:50, and reaction time 139 min; therefore, an optimal extraction rate of flavonoids of 0.2275% can be obtained. The chemical structure, surface morphology and element composition of flavonoid extracts were analyzed. The test results indicated that hemp extract contains flavonoids, which can be used to extract flavonoids from hemp fiber, so as to comprehensively develop hemp fiber and reduce the discharge of waste liquid in the traditional degumming process.

scholarly journals Research on Thermal Stability and Properties of Ca3ZrSi2O9 as Potential T/EBC Materials

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 583
Author(s):  
Yangyang Pan ◽  
Bo Liang ◽  
Yaran Niu ◽  
Dijuan Han ◽  
Dongdong Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Self Healing ◽  
Barrier Coating

In this study, a new coating material for thermal barrier coating (TBC) or environment barrier coating (EBC) application, Ca3ZrSi2O9 (CZSO), was synthesized and prepared by atmospheric plasma spray (APS) technology. The evolution of the phases and microstructures of the coatings with different thermal-aged were characterized by XRD, XRF, EDS and SEM, respectively. The thermal stability was measured by TG-DTA and DSC. The mechanical and thermal properties, including Vickers hardness (HV), fracture toughness (KIC), thermal conductivity () and coefficient of thermal expansion (CTE) were focused on. It was found that the as-sprayed CZSO coating contained amorphous phase. Crystalline transformation happened at 900–960 ∘C and no mass changes took place from room temperature (RT) to 1300 ∘C. The phenomena of microcrack self-healing and composition uniformity were observed during thermal aging. The of coating was very low at about 0.57–0.80 Wm−1K−1 in 200–1200 ∘C. The combined properties indicated that the CZSO coating might be a potential T/EBC material.

scholarly journals The Influence of Filler Size and Crosslinking Degree of Polymers on Mullins Effect in Filled NR/BR Composites

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2284
Author(s):  
Miaomiao Qian ◽  
Bo Zou ◽  
Zhixiao Chen ◽  
Weimin Huang ◽  
Xiaofeng Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Strain Energy ◽  
Mathematical Expression ◽  
Rubber Matrix ◽  
Mullins Effect ◽  
Butadiene Rubber ◽  
Crosslinking Degree ◽  
Test Range ◽  
Two Factors ◽  
The Matrix

Two factors, the crosslinking degree of the matrix (ν) and the size of the filler (Sz), have significant impact on the Mullins effect of filled elastomers. Herein, the result. of the two factors on Mullins effect is systematically investigated by adjusting the crosslinking degree of the matrix via adding maleic anhydride into a rubber matrix and controlling the particle size of the filler via ball milling. The dissipation ratios (the ratio of energy dissipation to input strain energy) of different filled natural rubber/butadiene rubber (NR/BR) elastomer composites are evaluated as a function of the maximum strain in cyclic loading (εm). The dissipation ratios show a linear relationship with the increase of εm within the test range, and they depend on the composite composition (ν and Sz). With the increase of ν, the dissipation ratios decrease with similar slope, and this is compared with the dissipation ratios increase which more steeply with the increase in Sz. This is further confirmed through a simulation that composites with larger particle size show a higher strain energy density when the strain level increases from 25% to 35%. The characteristic dependence of the dissipation ratios on ν and Sz is expected to reflect the Mullins effect with mathematical expression to improve engineering performance or prevent failure of rubber products.

scholarly journals Influence of Nanoparticles Reinforcements on Aluminium 6061 Alloys Fabricated via Novel Ultrasonic Aided Rheo-Squeeze Casting Method

2021 ◽  
Author(s):  
T. Arunkumar ◽  
Velmurugan Pavanan ◽  
Vijay Anand Murugesan ◽  
V. Mohanavel ◽  
Karthikeyan Ramachandran
Keyword(s):  
Squeeze Casting ◽  
Mechanical Performance ◽  
Thermal Studies ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Mechanical And Thermal Properties ◽  
The Novel ◽  
Morphological Studies ◽  
Agglomeration Of Nanoparticles ◽  
Disperse Nanoparticles

Abstract This study emphasis on a novel fabrication technique to fabricate hybrid cermets using Al 6061 alloy with nano sized SiC, Al2O3 and TiO2 as reinforcements. During the fabrication process, the melted pool was ultrasonicated to disperse nanoparticles at 20 kHz for 5 min and pressure of 50 MPa was applied to eliminate voids. The influence of nanoparticles on physical, thermal and mechanical properties were evaluated by tensile, wear and thermal studies. Cermets with Al2O3 reinforcements showed higher mechanical performance compared to Al alloy. This enhancement could be related to the uniform distribution of Al2O3 with refinement in grain size of Al alloy which was observed via surface analysis. The morphological studies provided justifiable evidence of homogeneous distribution, nominal cluster along with agglomeration and cavities shrinking on the cermets. The agglomeration of nanoparticles along with SiC protected the cermet in corrosion and abrasive wear by ~ 97% and ~ 71%. The study evidenced the novel fabrication method using ultrasonic rheo-squeeze casting led to improvement in mechanical and thermal properties of the hybrid cermets. Graphical abstract

scholarly journals Arc erosion behavior of TiB2/Cu composites with single-scale and dual-scale TiB2 particles

2019 ◽  
Vol 8 (1) ◽  
pp. 619-627 ◽  
Author(s):  
Shaolin Li ◽  
Xiuhua Guo ◽  
Shengli Zhang ◽  
Jiang Feng ◽  
Kexing Song ◽  
...  
Keyword(s):  
Erosion Resistance ◽  
Copper Matrix ◽  
Mechanical And Thermal Properties ◽  
Structure Defects ◽  
Arc Erosion ◽  
Single Scale ◽  
The Matrix ◽  
Tib2 Particles ◽  
Thermal Stability Of ◽  
Dual Scale

AbstractArc erosion behaviors of TiB2/Cu composites with single-scale and dual-scale TiB2 particles fabricated by powder metallurgy were studied. It was revealed that the dual-scale TiB2/Cu composites had fewer structure defects compared with the single-scale TiB2/Cu composites, and TiB2 particles with different size were uniformly distributed in the copper matrix. When the ratio of 2 μm over 50 μm TiB2 particles is 1:2, the density of TiB2/Cu composite is 98.5% and shows best mechanical and thermal properties. The arc duration and energy of TiB2/Cu composites increase with the increase of electric current in contact material testing. Compared with the single-scale TiB2/Cu composites, the arc erosion of dual-scale TiB2/Cu composite with 2 μm+50 μm (1:2) TiB2 was slighter. The anode bulge area and cathode erosion pit of dual-scale TiB2/Cu composite was smaller. The dual-scale TiB2 particles optimize the microstructure and thermal stability of the composite, which is conducive to alleviating arc erosion. The synergistic effect of different sized TiB2 particles in the matrix improved the arc erosion resistance of TiB2/Cu composite during arcing.

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