scholarly journals Static and dynamic mechanical behavior of doum palm (Hyphaene thebaica) nut reinforced HDPE composites

2021 ◽  
Vol 40 (4) ◽  
pp. 639-647
Author(s):  
A.A. Alabi ◽  
A.I. Obi ◽  
D.M. Kulla ◽  
S.M. Tahir
Keyword(s):  
Mechanical Properties ◽  
Dynamic Mechanical Properties ◽  
Particle Sizes ◽  
Load Bearing Capacity ◽  
Palm Fruit ◽  
Environmental Friendliness ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior ◽  
Static Mechanical ◽  
Static Mechanical Properties

The quest to discover more and to enhance the qualities of agro-residue for use as natural reinforcement of polymers continues to attract the attention of researchers because of the environmental friendliness. Hyphaene thebaica also known as doum palm is a fruit tree native to the Nile in Egypt and found in abundance in many parts of Africa. Doum palm fruit contains probably the hardest and toughest known nut. The doum palm nuts (DPN) are the most under-used hard-nut despite their abundance in nature. This study presents the potential doum palm nut particles (DPNp) as natural reinforcement for high density polyethylene (HDPE). Properties of DPN such as density, hardness and weight loss due to heating were determined. HDPE/DPNp composites were produced by reinforcing HDPE with 30, 35, 40 and 45% DPNp particles of two different sizes. The particle sizes 600 μm and 710 μm led to classifying the composites as X-composite and Y-composite respectively. The static and dynamic mechanical properties of the composites were determined and compared with the those of pure HDPE. Results showed that HDPE and DPNp can be formed into light and attractive components. Loading HPDE with DPNp significantly improve static mechanical properties of HDPE such as tensile strength, hardness, stiffness and resistance to impact failure by 50%, 200%, 800% and 1500% respectively. The HDPE/DPNp composites also had better dynamic mechanical properties. The ability of the composites to maintain load bearing capacity under dynamic conditions was superior to that of HDPE.

Effect of Sisal Fibre Hybridisation on Static and Dynamic Mechanical Properties of Corn/Sisal/Polylactide Composites

2017 ◽  
Vol 25 (6) ◽  
pp. 463-470 ◽  
Author(s):  
Honglin Luo ◽  
Dehui Ji ◽  
Guangyao Xiong ◽  
Lingling Xiong ◽  
Chuanyin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Dynamic Mechanical Properties ◽  
Peak Height ◽  
Sisal Fibre ◽  
Dynamic Mechanical ◽  
Static Mechanical ◽  
Tan Δ ◽  
First Time ◽  
Static Mechanical Properties

The relatively poor mechanical properties of corn fibre (CF) and its green composites have hindered its applications. In this work, sisal fibre (SF) was hybridised with CF to reinforce polylactide (PLA) composites (CF/SF/PLA). The static mechanical properties such as tensile, flexural and impact strengths and dynamic mechanical properties such as storage modulus (E’), damping behaviour (tan δ), glass transition temperature (Tg) of the hybrid composites were determined and, for the first time, hybrid effects on both static and dynamic mechanical properties were evaluated. It is found that the tensile, flexural, impact strengths, and E’ and tan δ peak height, as well as the hybrid effects change with hybrid ratio (SF:CF). It is demonstrated that a hybrid composite with desirable static and dynamic mechanical properties can be produced by optimising the fibre:hybrid ratio.

Dynamic Mechanical Properties of Grafted Polypropylene Composites Reinforced with Acetylated Wheat Straw Fibers

2015 ◽  
Vol 1767 ◽  
pp. 139-143
Author(s):  
Ramón Sánchez ◽  
Jacobo Aguilar ◽  
Silvia Y. Martínez ◽  
Reyes J. Sanjuan ◽  
Gerardo A. Mejía ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wheat Straw ◽  
Coupling Agent ◽  
Optical Microscope ◽  
Dynamic Mechanical Properties ◽  
Particle Sizes ◽  
Polypropylene Composites ◽  
Dynamic Mechanical ◽  
Twin Screw ◽  
Composite Pellets

ABSTRACTDynamic mechanical properties of polypropylene (PP) and grafted polypropylene (PP-g-MA) composites reinforced with acetylated wheat straw fibers (WSF) is reported in this work. The materials were prepared with different fiber particle sizes (40, 80 and 140 U.S. mesh) and at different fiber contents (5, 10 and 15 wt.%). The PP and PP-g-MA composites, where anhydride maleic (MA) was used as coupling agent, were obtained using a twin-screw extruder; whereas an injection-molding machine molded the composite pellets into testing specimens. To observe the morphology of the composites, micrographs were taken with an optical microscope. The Dynamic mechanical properties were analyzed using a torsional rheometer. The morphological analysis showed a high porous structure somehow similar to foamed materials. The storage modulus (G′) increased by increasing the fiber content, and decreased with fiber particle sizes for the PP composites. Meanwhile, the use of the coupling agent additive promoted a modulus increase due to higher fiber-polymer interaction, from better adhesion and chemical bonds formation between the fibers-coupling agent-PP.

EFFECT OF CARBON BLACK NATURE ON DYNAMIC MECHANICAL PROPERTIES AND REINFORCEMENT OF NR VULCANIZATION BY LATEX TECHNIQUES

2017 ◽  
Vol 90 (4) ◽  
pp. 611-620
Author(s):  
An Dong ◽  
Zhang Zhiyi ◽  
Jia Haixiang ◽  
Shou Jinquan ◽  
Zhang Huan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Dynamic Mechanical Properties ◽  
Mixing Process ◽  
Scanning Electron Micrograph ◽  
Dynamic Mechanical ◽  
Unit Operations ◽  
New Process ◽  
Static Mechanical ◽  
Filler Dispersion

ABSTRACT The influence of the structure and size of carbon black on the static mechanical and dynamic mechanical properties of filled natural rubber (NR) compounds is investigated in detail. A new process for the production of carbon black master batches with enhanced mechanical properties has been developed. The unit operations in the process are the preparation of carbon black slurry in the presence of a suitable surfactant, addition of the slurry to the fresh NR latex under stirring, coagulation of the mixture by the addition of acid, dewatering of the coagulum, and drying to obtain carbon black–incorporated NR. The competence of the new technique is established by comparing the characteristics of the carbon black–incorporated NR by the mill mixing process (control). The mechanical properties, including tensile strength, modulus, tear strength, and hardness, are superior for the vulcanization prepared by the latex-suspension coagulation techniques. The improvement shown by the vulcanization prepared by the latex-suspension coagulation techniques was attributed to the better filler dispersion evidenced from the scanning electron micrograph along with the attainment of a higher level of vulcanization.

PVA-Based Scaffolds for the Repair of Musculoskeletal Soft Tissue

2007 ◽  
Author(s):  
L. P. Serino ◽  
M. G. Cascone ◽  
L. Lazzeri ◽  
P. A. Torzilli ◽  
S. A. Maher
Keyword(s):  
Mechanical Properties ◽  
Phase Angle ◽  
Dynamic Modulus ◽  
Composite Scaffold ◽  
Dynamic Mechanical Properties ◽  
Cartilage Defects ◽  
Poly Vinyl Alcohol ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior

The objective of this study was to design a partly-degradable scaffold to repair cartilage defects. The scaffold, based on poly(vinyl alcohol), PVA, was intended to maintain long-term mechanical integrity and to facilitate cell proliferation via bioactive agent release from contained microparticles, made from either alginate, ALG or poly(lactic-co-glycolic acid), PLGA. The aim of this study was to characterize the morphological features and mechanical behaviour of composite scaffolds as a function of microparticle type and percent content. Our hypothesis was that the dynamic mechanical properties (Dynamic Modulus and Phase Angle) of the composite scaffold would not be affected by microparticle type, but that Dynamic Modulus would increase as a function of increased microparticle content. Scanning Electron Microscopy confirmed that the manufacturing process homogenously dispersed microspheres within the scaffolds. For pure PVA samples Dynamic Modulus ranged from 66±3 kPa at 0.01 Hz to 83±3 kPa at 50 Hz. As ALG microsphere content increased from 25% to 75%, Dynamic Modulus ranged from 92±5 kPa at 0.01 Hz to 153±19 kPa at 50 Hz. As the microsphere content increased from 25% to 75% PLGA, Dynamic Modulus ranged from 85±9 kPa at 0.01 Hz, to 157±16 kPa at 50 Hz. As expected, Dynamic Modulus increased with increasing test frequencies. For pure PVA specimens Phase Angle ranged from 4.3±0.8 degrees at 0.01 Hz to 12±1.2 degrees at 50 Hz. Phase Angle was not affected by microsphere content. In conclusion, the addition of microspheres affected the dynamic mechanical behavior, in particular Dynamic Modulus, of PVA scaffolds. However, the dynamic mechanical properties were not affected by the polymer from which the microspheres were manufactured. These findings suggest that microsphere type can be chosen to optimize the inclusion of bioactive factors, without detrimentally affecting the mechanical properties of the composite scaffold. It also suggests that % content of included microspheres can be used to modulate the mechanical properties of the scaffold at time zero.

Study on Physical and Dynamic Properties of BR Based Composites Filled with Different Particle Size of Magnesia

2012 ◽  
Vol 217-219 ◽  
pp. 165-173 ◽  
Author(s):  
Nai Xiu Ding ◽  
Fu Lan Hao ◽  
Lei Li ◽  
Wen Sun ◽  
Liang Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Physical Properties ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Frequency Mode ◽  
Particle Sizes ◽  
Payne Effect ◽  
Dynamic Mechanical

BR/MgO composites were prepared with seven kinds of particle sizes of MgO filled respectively. Effects of particle sizes on dynamic mechanical properties, vulcanization characteristics and physical properties of BR/MgO composites were studied. The results showed that the tensile strength of composites filled nanoscale of MgO was nine times of pure BR, and the vulcanization time was significantly shorter than that of composites filled with micron grade filler. The RPA experiments proved that the composites filled with MgO of 20nm and 50nm have greatly higher G＇, and that the G＇of the composites increase markedly while the value of tanδ decrease sharply with given temperature above 90 °C increasing. the higher value of tanδ at the frequency mode, and the obvious Payne effect compared with the composites filled micron grade of MgO

Effect of Molecular Weight on Dynamic Mechanical Properties of SKD cis-1,4-Butadiene Rubber

1967 ◽  
Vol 40 (2) ◽  
pp. 517-521
Author(s):  
A. I. Marei ◽  
E. A. Sidorovich
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Average Molecular Weight ◽  
Dynamic Mechanical Properties ◽  
Considerable Effect ◽  
Butadiene Rubber ◽  
Dynamic Mechanical ◽  
Temperature Range ◽  
Molecular Weights ◽  
Dynamic Mechanical Behavior

Abstract In the high-elastic temperature range the molecular weight has a considerable effect on the dynamic mechanical properties of linear (uncrosslinked) SKD cis-1, 4-butadiene rubber. In this temperature range an unequivocal correlation exists between the rebound resilience at a given temperature and the viscosity average molecular weight, and the determination of the resilience can therefore be recommended as a rapid method of finding the molecular weight of SKD. A similarity is found in the dynamic mechanical behavior of rubbers of different molecular weights in the high-elastic temperature range. In the low-temperature range an increase in the molecular weight of crystalline polymers of SKD is accompanied by an impairment of their elastic properties.

Effect of Particle Sizes on Rate Sensitivity and Dynamic Mechanical Properties of Polypropylene/Silica (PP/Sio2) Nanocomposites

2011 ◽  
Vol 364 ◽  
pp. 181-185 ◽  
Author(s):  
Firdaus Omar Mohd ◽  
Md Akil Hazizan ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Strain Rate ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Dynamic Mechanical Properties ◽  
Particle Sizes ◽  
Rate Condition ◽  
Dynamic Mechanical ◽  
Silica Nanocomposites

Filler-related characteristic such as particle size, shape and geometry are essential factors that need to be considered during the evaluation of the material’s performance especially in the area of particle filled composites. However, there is limited number of works are reported on this particular issue under high strain rate condition. Based on this concern, the paper presents an experimental results on the effect of particle sizes towards rate sensitivity and dynamic compressive properties of polypropylene/silica nanocomposites across strain rate from 10-2to 10-3s-1. The composite specimens were tested using universal testing machine for static loading and a compression split Hopkinson pressure bar apparatus for dynamic loading. Results show that, the stiffness and strength properties of polypropylene/silica nanocomposites were affected by the size of silica particles. However, the magnitudes of changed are somehow different between micro and nanosizes. On the other hand, particle size also plays a major contribution towards sensitivity of the polypropylene/silica nanocomposites where the smaller the reinforcement sizes, the less sensitive would be the composites. Overall, it is convenience to say that the particle size gives significant contribution towards rate sensitivity and dynamic mechanical properties of polypropylene/silica nanocomposites.

The Effect of Heat Treatment on Static and Dynamic Mechanical Properties of Rapidly Solidified and Plastically Consolidated RS442 Aluminium Alloy

2015 ◽  
Vol 641 ◽  
pp. 17-23
Author(s):  
Maciej Motyka ◽  
Tomasz Tokarski ◽  
Waldemar Ziaja ◽  
Mateusz Wedrychowicz
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloy ◽  
Bending Strength ◽  
Fatigue Behaviour ◽  
Extrusion Process ◽  
Dynamic Mechanical Properties ◽  
Static Mechanical ◽  
Rapidly Solidified ◽  
Static Mechanical Properties

Ultra-fine grained metallic materials are characterized by higher mechanical properties comparing with their conventional equivalents. However increase in strength under static load is not always accompanied by improved fatigue behaviour. Previous investigations on submicrocrystalline RS442 aluminium alloy produced by plastic consolidation of rapidly solidified flakes in the extrusion process revealed increase in its high cycle fatigue bending strength caused by annealing at 450°C. The aim of present studies was to evaluate the influence of heat treatment – also precipitation hardening – on static mechanical properties (hardness, tensile and yield strength) and fatigue strength of the alloy determined in high cycle stress controlled bending tests. Correlation between microstructure, static mechanical properties and fatigue behaviour was analyzed too.

Study on Shape-Memory Mechanism and Properties of NR/TPI Blends

2013 ◽  
Vol 467 ◽  
pp. 146-151 ◽  
Author(s):  
Guang Yi Lin ◽  
Shu Ming Liu ◽  
Fang Chen Dong
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Memory Performance ◽  
Dynamic Mechanical Properties ◽  
Memory Mechanism ◽  
Static Mechanical ◽  
Addition Level ◽  
Shape Fixity ◽  
Static Mechanical Properties

Crystalline grains of TPI distribute in NR/TPI blends in the role of physical crosslinking points and make up for deficiencies of the NR/TPI blending system. The flexibility and strength have been enhanced significantly by increasing the the addition level of TPI. The NR/TPI vulcanizates containing 30% of TPI were found to show the recovery rate of 99.4%, while the shape fixity was close to 100%. The study indicated that the recovery rates of NR/TPI vulcanizates depended to a large extent on the addition level of TPI. The influence of the addition level of TPI on the micro-structure of NR/TPI blends was investigated. In addition, the effects of TPI content on static mechanical properties, dynamic mechanical properties, shape-memory performance and cure characteristics of NR/TPI blends were also discussed.

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