scholarly journals Correlation between Mechanical Properties and Processing Conditions in Rubber-Toughened Wood Polymer Composites

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1170 ◽  
Author(s):  
Valentina Mazzanti ◽  
Lorenzo Malagutti ◽  
Andrea Santoni ◽  
Francesca Sbardella ◽  
Andrea Calzolari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wood Flour ◽  
Wood Fiber ◽  
Sharp Decrease ◽  
Processing Conditions ◽  
Wood Fibers ◽  
Screw Speed ◽  
Feeding Mode ◽  
Wood Polymer ◽  
The Cost

The use of wood fibers is a deeply investigated topic in current scientific research and one of their most common applications is as filler for thermoplastic polymers. The resulting material is a biocomposite, known as a Wood Polymer Composite (WPC). For increasing the sustainability and reducing the cost, it is convenient to increase the wood fiber content as much as possible, so that the polymeric fraction within the composite is thereby reduced. On the other hand, this is often thwarted by a sharp decrease in toughness and processability—a disadvantage that could be overcome by compounding the material with a toughening agent. This work deals with the mechanical properties in tension and impact of polypropylene filled with 50 wt.% wood flour, toughened with different amounts (0%, 10%, and 20%) of a polypropylene-based thermoplastic vulcanizate (TPV). Such properties are also investigated as a function of extrusion processing variables, such as the feeding mode (i.e., starve vs. flood feeding) and screw speed. It is found that the mechanical properties do depend on the processing conditions: the best properties are obtained either in starve feeding conditions, or in flood feeding conditions, but at a low screw speed. The toughening effect of TPV is significant when its content reaches 20 wt.%. For this percentage, the processing conditions are less relevant in governing the final properties of the composites in terms of the stiffness and strength.

Investigation of the Fracture of Resinated Single Wood Fibers in an Environmental Scanning Electron Microscope (Esem)

1998 ◽  
Vol 4 (S2) ◽  
pp. 838-839
Author(s):  
A. Egan ◽  
S. Shaler
Keyword(s):  
Mechanical Properties ◽  
Polymer Composite ◽  
Laser Scanning ◽  
Medium Density Fiberboard ◽  
Wood Fiber ◽  
Image Correlation ◽  
Environmental Scanning ◽  
Wood Fibers ◽  
Wood Polymer ◽  
Scanning Electron

Single fiber fracture is important in understanding the fundamental failure mechanisms in wood/polymer composite products such as medium density fiberboard (MDF). The mechanical properties and fracture behavior of individual wood fibers has only recently been observable using a combination of environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy and digital image correlation (DIC). Previous work has shown that specific areas on the fiber such as microcompressions and pits acted as crack nucelators and induce a brash fracture across the surface of the fiber. Given the development of these procedures it is now possible to observe and measure the mechanical properties and fracture characteristics of the wood fiber/ polymer composite fibers.Individual black spruce wood fibers were coated with diphenylmethane 4-4'diisocyanate resin containing Hostasol Red GG. The addition of the Hostasol Red flurochrome provided the option of quantifying resin coverage by fluorescence microscopy.

Effect of the delignification of wood fibers on the mechanical properties of wood fiber–polypropylene composites

2006 ◽  
Vol 102 (5) ◽  
pp. 4759-4763 ◽  
Author(s):  
Alinaghi Karimi ◽  
Saleh Nazari ◽  
Ismaeil Ghasemi ◽  
Mehdi Tajvidi ◽  
Ghanbar Ebrahimi
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Wood Fibers ◽  
Polypropylene Composites

Accelerated Weathering of Modified Wood Flour Plastic Composites

2007 ◽  
Vol 29-30 ◽  
pp. 315-318 ◽  
Author(s):  
J.S. Fabiyi ◽  
A.G. McDonald
Keyword(s):  
Color Change ◽  
Wood Flour ◽  
Wood Fiber ◽  
Color Measurement ◽  
Accelerated Weathering ◽  
Wood Fibers ◽  
Pyrolysis Gas ◽  
Color Changes ◽  
Plastic Composites ◽  
Gas Chromatograph Mass Spectrometry

The effect of accelerated weathering on the chemical and color of wood plastic composites (WPC) made from modified pine wood fiber (control, extractives free and holocellulose) was investigated. WPC were produced from the various wood fibers (60%, weight) and high density polyethylene (40%, weight) as matrix were subjected to accelerated weathering in xenon-arc weatherometer for up to 1200 hours. This study aimed at getting a better understanding of the chemical changes that occur to weathered WPC relative to its material compositions (wood and plastic). Chemical analyses and color measurement of the weathered surface using Fourier transform infrared (FTIR) spectroscopy, pyrolysis gas chromatograph mass spectrometry and colorimetery showed that degradation of WPC had occurred, causing color changes. It was observed that WPC made from holocellulose wood fiber had the lowest color change compared to extractives free wood and control wood fiber based WPC.

scholarly journals A novel DOPO-g-KH550 modification wood fibers and its effects on the properties of composite phenolic foams

2018 ◽  
Vol 20 (2) ◽  
pp. 47-53 ◽  
Author(s):  
Yufeng Ma ◽  
Xiang Geng ◽  
Xi Zhang ◽  
Chunpeng Wang ◽  
Fuxiang Chu
Keyword(s):  
Mechanical Properties ◽  
Phenolic Resin ◽  
Wood Fiber ◽  
Treated Wood ◽  
Comprehensive Analysis ◽  
Wood Fibers ◽  
H Nmr ◽  
Interfacial Compatibility ◽  
Ft Ir ◽  
Diffraction Peaks

Abstract A novel 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) graft γ-amino propyl triethoxy silane (KH550) was synthesized and introduced on the surface of wood fiber. Finally DOPO-g-KH550 treated wood fiber (DKTWF) was used to prepare DKTWF composite phenolic foams (DKTWFCPF). The structures of DOPO-g- KH550 was acknowledged by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H-NMR). The structures of DKTWF were confirmed by FT-IR. Compared with wood fiber, the diffraction peaks’ position was basically unchanged, but the crystallinity was slightly increased and thermal stability were dramatically improved, T5% and Tmax increased by 21.9o and 36.1o respectively. But the char yield (800o) was slightly reduced. With the dosage of DKWF, there were different degrees of improvement including the mechanical properties, flame retardancy and microstructure of DKTWFCPF. Comprehensive analysis, the interfacial compatibility was significantly improved between DKTWF and phenolic resin, and the suitable content of DKTWF was 4%.

scholarly journals Influence of Veneer Density on Plywood Thickness and Some Mechanical Properties

2021 ◽  
Vol 46 (341) ◽  
pp. 66-74
Author(s):  
Laimonis Kūliņš ◽  
Anete Meija ◽  
Rihards Roziņš ◽  
Kārlis Hermanis Liepa ◽  
Uldis Spulle
Keyword(s):  
Mechanical Properties ◽  
Symmetry Axis ◽  
Scientific Literature ◽  
Common Knowledge ◽  
Wood Fiber ◽  
Solid Wood ◽  
Wood Fibers ◽  
Tensile Shear ◽  
Wood Moisture ◽  
Direct Production

Abstract It has been common knowledge that as the density of wood increases, the mechanical properties also improve. In turn, the density of wood depends on many factors, including the wood moisture content, location and cross-section in the trunk, the type of treatment and the parameters of technological processes. There is a great deal of research reported in the scientific literature on the effect of solid wood density on mechanical properties for different wood species as well as for structural timber. However, no research data can be found related investigation of the influence of veneer density on the properties of the birch plywood. In the present study, researching the properties of 7-ply birch plywood (thickness 9 mm), it was concluded that as the density of veneers increases, the bending properties of plywood in the direction of wood fibers (covered veneers) increases. When determining the plywood gluing quality, similar tendencies have been observed. For plywood with a lower density in all veneer plies the gluing quality (tensile-shear test) for perpendicular wood fiber veneers increases in the direction from the symmetry axis or middle veneer to the plywood outer plies, which can be explained by the fact that the outer plies become denser at the time of the hot pressing process. The results of the study will allow birch plywood manufacturers in direct production, sort veneers by density, to produce plywood with very predictable gluing quality, plywood thickness and mechanical properties in bending.

The effect of processing conditions on the mechanical properties and morphology of self-reinforced wood-polymer composite

2013 ◽  
Vol 34 (10) ◽  
pp. 1567-1574 ◽  
Author(s):  
Jianchen Cai ◽  
Mingyin Jia ◽  
Ping Xue ◽  
Yun Ding ◽  
Xiang Zhou
Keyword(s):  
Mechanical Properties ◽  
Polymer Composite ◽  
Processing Conditions ◽  
Wood Polymer ◽  
Wood Polymer Composite

Influence of EVA Content on the Properties of Extrusion Molding WPCS

2012 ◽  
Vol 557-559 ◽  
pp. 1378-1382
Author(s):  
Xiao Hong Hu ◽  
Dong Fang Li ◽  
Ji Hang Hu ◽  
Li Li
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Wood Flour ◽  
Wood Fiber ◽  
Reflectance Spectroscopy ◽  
Surface Groups ◽  
Comprehensive Performance ◽  
Scanning Electron

EVA was tried to improve the compatibility between wood flour and plastics substrate as a new kind of coupling agent. Infrared diffuse reflectance spectroscopy was applied to examine the changes in surface groups. The influence of the EVA content on the mechanical properties of WPCs was investigated and the morphologies of fractured surfaces were examined using a scanning electron microscope (SEM). Infrared diffuse reflectance spectroscopy shows that the EVA reduced the polarity of the wood flour. When the content of EVA is increased the mechanical properties of WPCs also increased. The SEM showed that EVA can help improve the interface compatibility between the fiber and plastic by aiding in the bonding of more plastic to the wood fiber. The comprehensive performance of the WPCs reached its maximum potential when the EVA level was at 15%.

Effects of Several Ingredient Variables on Mechanical Properties of Wood Fiber-Polyolefin Composites Blended in a Thermokinetic Mixer

1992 ◽  
Vol 266 ◽  
Author(s):  
C. Gonzalez ◽  
C. M. Clemons ◽  
G. E. Myers ◽  
T. M. Harten
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Wood Flour ◽  
Wood Fiber ◽  
Cellulose Fiber ◽  
Maleated Polypropylene ◽  
Pure Cellulose ◽  
Dispersing Agent ◽  
Equivalent Strength ◽  
Fibrous Fillers

AbstractWe examined the influence of several variables on the mechanical properties of wood fiber-polyolefin composites blended in a thermokinetic mixer. A pure cellulose fiber and fibers from old newspaper provided similar performance in matrices of virgin polypropylene or recycled milk bottles (high density polyethylene). Relative to wood flour, these fibrous fillers led to greater strength and modulus with both plastics, to lower impact energy with polyethylene, and to similar impact energy with polypropylene. Compared with the existing commercial wood flour-polypropylene system, the totally recycled polyethylene-newspaper composite provided equivalent strength and modulus, along with greater notched impact energy. Little difference was seen in composites containing a maleated polypropylene additive in the form of the solid anhydride or the emulsified potassium salt, indicating that the additive acted as a dispersing agent and not as a strong coupling agent.

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