Gold as an X-ray CT scanning contrast agent: Effect on the mechanical properties of wood plastic composites

Holzforschung ◽  
2007 ◽  
Vol 61 (6) ◽  
pp. 723-730 ◽  
Author(s):  
Yi Wang ◽  
Lech Muszynski ◽  
John Simonsen
Keyword(s):  
Tensile Properties ◽  
Mechanical Performance ◽  
Imaging Techniques ◽  
Ct Scanning ◽  
Nano Particles ◽  
Wood Plastic Composites ◽  
X Ray ◽  
Micro Particles ◽  
Plastic Composites ◽  
Gold Nano Particles

Abstract Wood plastic composites (WPCs) are typically composed of wood particles, thermoplastic polymers and small amounts of additives. Further improvement of WPC technology requires a better understanding of their mechanical performance and durability on the micro level. X-ray computed tomography (CT) and advanced imaging techniques can provide visualization and support characterization of the internal structure, deformation and damage accumulation in WPCs under loading and various environmental exposures. However, both wood and thermoplastics are weakly attenuating materials for X-ray and good contrast between these two components is difficult to obtain. In the present study, chemically inert gold nano-particles and micro-particles were investigated as contrast agents to improve X-ray CT scanning contrast between wood and thermoplastics. The effect of adding 1% (by wt.) gold nano- and micro-particles on the tensile properties of wood/high-density polyethylene composites was addressed. Samples with and without surfactant were tested in tension and scanned on a custom desktop X-ray CT system. It was found that the addition of gold particles did not impair the WPC tensile properties. However, some of the tensile properties were significantly affected if the surfactant was included. Gold micro-particles were shown to disperse well without surfactant and significantly improve the X-ray CT scanning contrast between wood and polymer, while gold nano-particles (without surfactant) did not disperse well and do not contribute to contrast improvement.

The utilization of organic vermiculite to reinforce wood–plastic composites with higher flexural and tensile properties

2013 ◽  
Vol 51 ◽  
pp. 310-316 ◽  
Author(s):  
Xiang Li ◽  
Bingrong Lei ◽  
Zhidan Lin ◽  
Langhuan Huang ◽  
Shaozao Tan ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Wood Plastic Composites ◽  
Plastic Composites

Properties of wood-plastic composites (WPCs) reinforced with extracted and delignified wood flour

Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 933-940 ◽  
Author(s):  
Yao Chen ◽  
Nicole M. Stark ◽  
Mandla A. Tshabalala ◽  
Jianmin Gao ◽  
Yongming Fan
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Mechanical Performance ◽  
Wood Flour ◽  
Hot Water ◽  
Sodium Chlorite ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Acetone Water ◽  
Full Factorial Experimental Design

Abstract The water sorption and mechanical properties of wood-plastic composites (WPCs) made of extracted and delignified wood flour (WF) has been investigated. WF was prepared by extraction with the solvent systems toluene/ethanol (TE), acetone/water (AW), and hot water (HW), and its delignification was conducted by means of sodium chlorite/acetic acid (AA) solution. A 24 full-factorial experimental design was employed to determine the effects of treatments and treatment combinations. WPCs were prepared with high-density polyethylene (HDPE) and treated WF was prepared by means of extrusion followed by injection molding, and the water absorption characteristics and mechanical properties of the products were evaluated. WPCs produced with extracted WF had lower water absorption rates and better mechanical properties than those made of untreated WF. WPCs containing delignified WF had higher water absorption rates and improved mechanical performance compared with those made of untreated WF.

Fundamental Studies on Wood-Plastic Composites: Effects of Cellulase Treatment on Hybrid Pennisetum Powder

2011 ◽  
Vol 239-242 ◽  
pp. 2638-2641
Author(s):  
Jun Mu ◽  
Yong Shun Feng ◽  
De Rong Zhang ◽  
Zhi Li Wang ◽  
Hong Bin Wang
Keyword(s):  
Mechanical Properties ◽  
Treatment Time ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
Wood Plastic Composites ◽  
X Ray ◽  
Plastic Composites ◽  
Cellulase Treatment ◽  
Interfacial Compatibility ◽  
Hybrid Pennisetum

Studies on interfacial compatibility of wood plastic composites(WPCs) have received considerable attention in recent years. The effects on the surface modification by cellulase treatment and the mechanical properties of prepared WPCs were investigated in this study. X-ray diffraction(XRD) results show that the relative crystallinity(RC) of Hybrid Pennisetum(HP) could be significantly changed by the cellulase treatment. The RC of HP powders mainly goes through a phase that it first increases and then decreases by the treatment of cellulase. Five groups of different cellulase dosage and different treatment time were selected to do the mechanical and DMA tests. With proper dosage of cellulase and treatment time, the mechanical properties of WPCs could be improved. Finally, in the case of HP powder/cellulase of 4/1 and treatment time for 2 hours, WPCs show the best performance.

scholarly journals Effect of Hybrid Talc-Basalt Fillers in the Shell Layer on Thermal and Mechanical Performance of Co-Extruded Wood Plastic Composites

Materials ◽  
2015 ◽  
Vol 8 (12) ◽  
pp. 8510-8523 ◽  
Author(s):  
Runzhou Huang ◽  
Changtong Mei ◽  
Xinwu Xu ◽  
Timo Kärki ◽  
Sunyoung Lee ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Shell Layer ◽  
Wood Plastic Composites ◽  
Plastic Composites

scholarly journals The Effect of Varying the Amount of Short Hemp Fibers on Mechanical and Thermal Properties of Wood–Plastic Composites from Biobased Polyethylene Processed by Injection Molding

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 138
Author(s):  
Celia Dolçà ◽  
Eduardo Fages ◽  
Eloi Gonga ◽  
David Garcia-Sanoguera ◽  
Rafael Balart ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Injection Molding ◽  
Mechanical Performance ◽  
Natural Fibers ◽  
Mechanical And Thermal Properties ◽  
Standard Samples ◽  
Wood Plastic Composites ◽  
Hemp Fibers ◽  
Plastic Composites ◽  
Twin Screw

Biobased HDPE (bioHDPE) was melt-compounded with different percentages (2.5 to 40.0 wt.%) of short hemp fibers (HF) as a natural reinforcement to obtain environmentally friendly wood plastic composites (WPC). These WPC were melt-compounded using a twin-screw extrusion and shaped into standard samples by injection molding. To improve the poor compatibility between the high non-polar BioHDPE matrix and the highly hydrophilic lignocellulosic fibers, a malleated copolymer, namely, polyethylene-graft-maleic anhydride (PE-g-MA), was used. The addition of short hemp fibers provided a remarkable increase in the stiffness that, in combination with PE-g-MA, led to good mechanical performance. In particular, 40 wt.% HF drastically increased the Young’s modulus and impact strength of BioHDPE, reaching values of 5275 MPa and 3.6 kJ/m2, respectively, which are very interesting values compared to neat bioHDPE of 826 MPa and 2.0 kJ/m2. These results were corroborated by dynamic mechanical thermal analysis (DMTA) results, which revealed a clear increasing tendency on stiffness with increasing the fiber loading over the whole temperature range. The crystal structure was not altered by the introduction of the natural fibers as could be seen in the XRD patterns in which mainly the heights of the main peaks changed, and only small peaks associated with the presence of the fiber appeared. Analysis of the thermal properties of the composites showed that no differences in melting temperature occurred and the non-isothermal crystallization process was satisfactorily described from the combined Avrami and Ozawa model. As for the thermal degradation, the introduction of HF resulted in the polymer degradation taking place at a higher temperature. As for the change in color of the injected samples, it was observed that the increase in fiber generated a clear modification in the final shades of the pieces, reaching colors very similar to dark woods for percentages higher than 20% HF. Finally, the incorporation of an increasing percentage of fibers also increased water absorption due to its lignocellulosic nature in a linear way, which drastically improved the polarity of the composite

Characterisation of the physical, chemical and mechanical properties of a radiopaque polyethylene

2020 ◽  
Vol 35 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Fedra P Zaribaf ◽  
Harinderjit S Gill ◽  
Elise C Pegg
Keyword(s):  
Molecular Weight ◽  
Contrast Agent ◽  
Tensile Properties ◽  
High Molecular Weight ◽  
Imaging Techniques ◽  
X Ray ◽  
Physical Chemical ◽  
Diffusion Parameters ◽  
Low X ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene has a low X-ray attenuation, hence, the performance of the polyethylene implants used for joint replacements cannot be directly investigated using X-ray-based imaging techniques. In this study, the X-ray attenuation of polyethylene was increased by diffusing an FDA-approved oil-based contrast agent (Lipiodol ultra fluid) into the surface of the samples, and the suitability of this novel radiopaque ultra-high molecular weight polyethylene for clinical applications was examined. Different levels of radiopacity were created by controlling the diffusion parameters, and the level of radiopacity was quantified from computed tomography scans and reported in Hounsfield units. The physical, chemical and tensile properties of the radiopaque ultra-high molecular weight polyethylene were examined and compared to untreated and thermally treated controls. The results of this study confirmed that for the samples treated at 115°C or less the diffusion of the contrast agent did not significantly alter the crystallinity ( p = 0.7) or melting point ( p = 0.4) of the polyethylene. Concomitantly, the tensile properties were not significantly different from the control samples ( p > 0.05 for all properties). In conclusion, the radiopaque ultra-high molecular weight polyethylene treated for less than 18 h at a temperature of 115°C or below is a promising candidate for joint replacement applications as it can be identified in a standard X-ray while retaining the tensile properties of clinically used radiolucent ultra-high molecular weight polyethylene.

scholarly journals Studies on Mechanical Performance of Wood-Plastic Composites: Polystyrene-Eucalyptus globulus Labill

BioResources ◽  
2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Miguel Ángel Flores-Hernández ◽  
José Guillermo Torres-Rendón ◽  
Rosa María Jiménez-Amezcua ◽  
María Guadalupe Lomelí-Ramírez ◽  
Francisco Javier Fuentes-Talavera ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Mechanical Performance ◽  
Wood Plastic Composites ◽  
Plastic Composites

scholarly journals Utilization of demolition wood and mineral wool wastes in wood-plastic composites

Detritus ◽  
2020 ◽  
pp. 19-25
Author(s):  
Petri Jetsu ◽  
Markku Vilkki ◽  
Ismo Tiihonen
Keyword(s):  
Mechanical Performance ◽  
Strength Properties ◽  
Mineral Wool ◽  
Construction And Demolition Waste ◽  
Waste Materials ◽  
Demolition Waste ◽  
Waste Wood ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
A Minor

Wood and mineral wool fractions from demolished buildings were sorted into different categories and processed to the suitable grain size needed for the manufacturing of wood-plastic composites. Processed construction and demolition waste materials mixed with plastics and additives were extruded into hollow test bars using a conical rotary extruder. Test specimens needed for measurements were cut from test bars. The results showed that the mechanical performance of wood-plastic composites based on construction and demolition waste wood, and mineral wool was at a good level and comparable to commonly used wood-plastic composites in decking applications. The highest strength properties of wood-plastic composites were achieved with a plywood fraction and the lowest with materials containing a particle/fibre board fraction. The mechanical performance can be improved by utilizing mineral wool in the formulation of wood-plastic composites. A material mixture containing several wood fractions as well as mineral wool also gave good strength properties. Only a minor reduction in strength properties was measured when recycled plastic was utilized meaning that wood-plastic composites suitable for many types of applications can be produced entirely from recycled materials.

scholarly journals The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiping Wu ◽  
Na Hu ◽  
Yiqiang Wu ◽  
Shuyun Wu ◽  
Zu Qin
Keyword(s):  
Thermogravimetric Analysis ◽  
Tensile Properties ◽  
Magnesium Hydroxide ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Combustion Process ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Cone Calorimeter Test

The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.

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