scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

scholarly journals Modulating the Mechanical Properties of Electrospun PHB/PCL Materials by Using Different Types of Collectors and Heat Sealing

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 693 ◽  
Author(s):  
Irena Borisova ◽  
Olya Stoilova ◽  
Nevena Manolova ◽  
Iliya Rashkov
Keyword(s):  
Mechanical Properties ◽  
Mechanical Tests ◽  
Fibrous Materials ◽  
Scanning Calorimetry ◽  
Before And After ◽  
Ft Ir ◽  
Improved Performance ◽  
Tunable Mechanical Properties ◽  
Cutting Direction ◽  
Ft Ir Spectroscopy

Two-component fibrous materials based on poly(3-hydroxybutyrate) (PHB, Tm = 160 °C) and poly(ε-caprolactone) (PCL, Tm = 60 °C) were successfully fabricated by dual-jet electrospinning of their separate spinning solutions. The desired alignment of the fibers that compose PHB/PCL mats was achieved by using three types of rotating collectors—drum (smooth), blade and grid. Additional fiber alignment in the direction of collector rotation was achieved by rotating at 2200 rpm. Moreover, the selected concentration of PCL spinning solution resulted in fibers with spindle-like defects along their length. Thus, “segment” sealing of the PHB (high-melting) fibers by the molten PCL (low-melting) fibers/defects sites was achieved after heating the PHB/PCL mats above the melting temperature (Tm) of PCL. The surface morphology, thermal behavior and mechanical properties of the PHB/PCL mats before and after thermal treatment were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and mechanical tests. The results indicated that regardless of the cutting direction of the specimens (0° or 90°), thermal treated PHB/PCL mats reveal enhanced mechanical properties. Therefore, this work provides an easily feasible route for the fabrication of electrospun PHB/PCL mats with tunable mechanical properties and improved performance.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

scholarly journals Tension mechanical properties of recycled glass-epoxy composite material

2012 ◽  
pp. 189-198 ◽  
Author(s):  
Jelena Petrovic ◽  
Darko Ljubic ◽  
Marina Stamenovic ◽  
Ivana Dimic ◽  
Slavisa Putic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Modulus Of Elasticity ◽  
Epoxy Composite ◽  
Raw Materials ◽  
Mechanical Tests ◽  
Recycled Glass ◽  
Before And After

The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite materials. This study represents a contribution to the field of mechanical properties of the recycled composite materials. The tension mechanical properties (tensile strength and modulus of elasticity) of once used and disposed glass-epoxy composite material were compared before and after the recycling. The obtained results from mechanical tests confirmed that the applied recycling method was suitable for glass-epoxy composite materials. In respect to the tensile strength and modulus of elasticity it can be further assessed the possibility of use of recycled glass-epoxy composite materials.

scholarly journals Research and Performance Test of New Full-Length Anchorage Material

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Shunjie Huang ◽  
Xiangrui Meng ◽  
Guangming Zhao ◽  
Yingming Li ◽  
Xiang Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Performance Test ◽  
Strong Stability ◽  
Full Length ◽  
Anchor Cable ◽  
New Material ◽  
Anchoring Strength ◽  
The Stability ◽  
Ultrafine Cement

It is difficult to support roadway with anchor cable in view of impact tendency in impinging liability roadway; a new material of inorganic and high-performance full-length anchoring material for anchoring cable is developed by adding several modifiers with ultrafine cement as the main material. The purpose is to improve the mechanical properties and durability of cement-based materials, improve the coordination of anchor cable support system, and ensure the stability of surrounding rock of mining roadway. The new full-length anchoring material is developed by optimizing the proportion of different components of the material, and the mechanical properties of the new material were studied. The anchoring force of resin anchoring agent, ordinary Portland cement, blank ultrafine cement, and new full-length anchoring material are tested. Based on SEM microscopic characterization, the fracture types and failure characteristics of resin anchoring agent and full-length anchoring material are researched. The results show that the optimal content of each component of the new inorganic high-performance full-length anchorage material is as follows: the content of component A is 15%, the content of component B is 3%, the content of component C is 0.2%, the content of component D is 1%, and the content of component E is 1%; the tensile test shows that the full-length anchoring material has good bonding property, high anchoring strength, strong stability, and good rock coupling. SEM microstructure and morphology analysis have showed that the new anchorage materials can fully hydrate each other, resulting in a relatively dense stone body. The new full-length anchoring material can effectively improve the anchoring force and improve the stability of the anchor cable and has significant performance advantages and good engineering applicability, and it has the advantages of lower cost and safer to use. The new material is a very good supporting material for roadway.

Temperature Effect on the Mechanical Properties of Very High Performance Concrete

2018 ◽  
Vol 34 ◽  
pp. 29-39
Author(s):  
Mebarek Belaoura ◽  
Dalila Chiheb ◽  
Mohamed Nadjib Oudjit ◽  
Abderrahim Bali
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Exothermic Reaction ◽  
Physical And Mechanical Properties ◽  
Mass Effect ◽  
Mechanical Tests ◽  
Conventional Concrete ◽  
Very High

This study aims at a better understanding of the behaviour of very high performance concretes (VHPC) subjected to high temperatures. The temperature increase within the concrete originating from the hydratation exothermic reaction of cement is emphasized by the mass effect of the structures and can lead to thermal variations of around 50°C between the heart and the structures walls. These thermal considerations are not without consequence on durability and the physical and mechanical properties of very high performance concrete, such as the compressive strength. This work is an experimental research that shows the effects of temperature on the mechanical properties of very high performance concrete (VHPC) and compares them with those of conventional concrete and HPC. Test specimens in usual concrete, HPC and VHPC are made, preserved till maturity of the concrete, and then subjected to a heating-cooling cycle from room temperature to 500°C at heating rate 0.1°C/min. Mechanical tests on the hot concrete and cooling (air and water) were realized. The results show that the mechanical characteristics of VHPC (density, compressive strength, tensile strength and elastic modulus) decrease with increasing temperature, but their strength remains higher than that of conventional concrete.

scholarly journals Mechanical Properties and Weathering Behavior of Polypropylene-Hemp Shives Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Marcel Ionel Popa ◽  
Silvia Pernevan ◽  
Cecilia Sirghie ◽  
Iuliana Spiridon ◽  
Dorina Chambre ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Degradation ◽  
Accelerated Weathering ◽  
Ir And Raman Spectroscopies ◽  
Before And After ◽  
Ft Ir ◽  
Main Components ◽  
Poly Propylene ◽  
Ir And Raman

This paper presents the obtaining and the characterization of composites with polypropylene matrix and hemp shives as filler in different ratios and containing poly(propylene)-co maleic anhydride (MAH-PP) 3% wt as compatibility agent. The weathering behavior of the composite enclosing 60% hemp shives, performed after the exposure to UV radiations at different exposure times, was evaluated. The changes in the chemical and morphological structures were investigated by FT-IR and RAMAN spectroscopies and AFM microscopy. The mechanical characteristics of the composites were determined before and after an artificial aging process, and they are within the limits of the values reported for polyolefin-based composites and materials with natural fillers. During the accelerated weathering process, the correlation between the chemical degradation of the main components of the composite and the modification of the mechanical properties after the process of aging has been observed.

Microstructure and Mechanical Properties of Inconel 718 Produced by SLM and Subsequent Heat Treatment

2015 ◽  
Vol 651-653 ◽  
pp. 665-670 ◽  
Author(s):  
Anatoly A. Popovich ◽  
Vadim Sh. Sufiiarov ◽  
Igor A. Polozov ◽  
Evgenii V. Borisov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Inconel 718 ◽  
Elevated Temperatures ◽  
Ductile Failure ◽  
Mechanical Tests ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The article presents results of selective laser melting of Inconel 718 superalloy. It was studied phase microstructure of the material obtained by selective laser melting and also the material after heat treatment. The phase composition of the initial powder material, the specimens after selective laser melting before and after heat treatment was studied. The effect of heat treatment on microstructure and mechanical properties of the specimens was shown. It was studied the mechanical behavior of the manufactured specimens before and after heat treatment at room and elevated temperatures as well. The results of impact tests and fractography of the specimens are presented. Mechanical tests showed that the specimens after heat treatment have decent mechanical properties comparable to hot-rolled material. Fractography showed that the obtained material is characterized by ductile failure mode with local elements of brittle fracture.

Mechanical Properties of Aramid Composite as an Alternative in Use of Steel on the Manufacture of CN-235 Aircraft Wings

2021 ◽  
Vol 1025 ◽  
pp. 53-59
Author(s):  
Febrianti Nurul Hidayah ◽  
Ikha Farikha ◽  
Donald Edwin Maspaitella
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Minimum Weight ◽  
Mechanical Tests ◽  
Interlaminar Shear Strength ◽  
Shear Tests ◽  
Aircraft Wings ◽  
Strength Tests ◽  
Insignificant Difference ◽  
Interlaminar Shear

The use of steel in aerospace manufacture continues to decrease, owing in part to the sustainability and mechanical properties of fibers which have higher strength in minimum weight than steel. This study was defined to evaluate the mechanical properties of high-performance fibers, especially aramid, in terms of composite to be part of aircraft' wings called CN-235. The reinforcements were pre-impregnated by the materials manufacturers, under heat and pressure, with a pre-catalysed resin. Then the layering of aramid prepregs was carried with a dry lay-up process and cured in the autoclave at a temperature of 125°C and pressure of 3 bar for 90 minutes. The aramid composite was cured in various grain directions and examined in mechanical tests such as tensile, compression, and interlaminar shear strength tests. The result showed an insignificant difference between 0 and 90 degrees of grain direction in aramid composite in any properties. The strength of aramid composite with 90 degrees of grain direction has a higher value in the compression test (less than 5%) while having lower value in tensile and interlaminar shear tests.

scholarly journals Removal of Tetracycline from Aqueous Solution Using Nanocomposite Based on Polyanion-Modified Laterite Material

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Thi Hau Vu ◽  
Thi Mai Viet Ngo ◽  
Thi Tu Anh Duong ◽  
Thi Hien Lan Nguyen ◽  
Xuan Truong Mai ◽  
...  
Keyword(s):  
High Performance ◽  
Polystyrene Sulfonate ◽  
Bet Method ◽  
Before And After ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Solid Liquid ◽  
Kinetics Of ◽  
And Diffusion ◽  
Good Agreement

This work investigated the removal of antibiotic tetracycline (TC) from wastewater using nanocomposite material based on laterite modified with polyanion, polystyrene sulfonate (PSS). The effective factors influenced on the TC removal using nanocomposite PSS-modified laterite (NCPML) were optimized and found to be pH 4, solid-liquid ratio 5 mg/mL, and contact time 180 min. The highest removal of TC reached about 88% under the optimum adsorption conditions. The adsorption isotherm and kinetics of TC adsorption onto NCPML were in good agreement with the Langmuir and pseudo-second-order models, respectively. The characteristics of the NCPML material before and after TC adsorption were examined by zeta (ζ) potential measurements, Brunauer–Emmett–Teller (BET) method, and Fourier transform infrared spectroscopy (FT-IR). The TC adsorption onto NCPML was induced by electrostatic interaction, hydrogen bonding, and diffusion interaction. The TC removal from wastewater was approximately 94% while efficiency still reached 66% after five regenerations. Our research reveals that NCPML is a high-performance adsorbent for TC removal from wastewater.

scholarly journals Implementation of a Recycled Polypropylene Homopolymer Material for Use in Additive Manufacturing

2021 ◽  
Vol 13 (9) ◽  
pp. 4990
Author(s):  
Jozef Dobránsky ◽  
Martin Pollák ◽  
Luboš Běhálek ◽  
Jozef Svetlík
Keyword(s):  
Mechanical Properties ◽  
Charpy Impact ◽  
Mechanical Tests ◽  
Scientific Article ◽  
Testing Method ◽  
New Material ◽  
Flexural Tests ◽  
The Individual ◽  
Percentage Ratio ◽  
Recycled Material

The main objective of the presented scientific article is to define the mechanical properties of polypropylene homopolymer with a prescribed percentage ratio of recycled granulate. The chosen material is intended for injection molding and especially for the production of products made by additive technologies. Experimental verification of the mechanical properties was realized by testing samples produced with various concentrations of the recycled material. Experimental samples underwent tests to obtain the mechanical properties of the produced new material. These tests included rheological tests, tensile and flexural tests as well as and Charpy impact toughness tests. These mechanical tests were conducted according to ISO standards valid for the individual testing method. Testing methods were carried out using prescribed numbers of testing samples. The presented scientific article is also focused on changes in microstructures of testing materials in relation to the percentage ratio of recycled granulate. Recycled granulate of thermoplastic was not necessity for additional modifications.

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