scholarly journals Effect of Heat Treatment on the Chemical Structure and Thermal Properties of Softwood-Derived Glycol Lignin

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1167 ◽  
Author(s):  
Thi Thi Nge ◽  
Yuki Tobimatsu ◽  
Masaomi Yamamura ◽  
Shiho Takahashi ◽  
Eri Takata ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Large Scale ◽  
Lignin Content ◽  
Japanese Cedar ◽  
Forest Products ◽  
Structural Rearrangement ◽  
Industrial Applications ◽  
Wood Meal ◽  
Heat Treated

A large-scale glycol lignin (GL) production process (50 kg wood meal per batch) based on acid-catalyzed polyethylene glycol (PEG) solvolysis of Japanese cedar (JC) was developed at the Forestry and Forest Products Research Institute (FFPRI), Tsukuba, Japan. JC wood meal with various particle size distributions (JC-S < JC-M < JC-L) (average meal size, JC-S (0.4 mm) < JC-M (0.8 mm) < JC-L (1.6 mm)) and liquid PEG with various molecular masses are used as starting materials to produce PEG-modified lignin derivatives, namely, GLs, with various physicochemical and thermal properties. Because GLs are considered a potential feedstock for industrial applications, the effect of heat treatment on GL properties is an important issue for GL-based material production. In this study, GLs obtained from PEG400 solvolysis of JC-S, JC-M, and JC-L were subjected to heating in a constant-temperature drying oven at temperatures ranging from 100 to 220 °C for 1 h. All heat-treated GL series were thermally stable, as determined from the Klason lignin content, TMA, and TGA analyses. SEC analysis suggests the possibility of condensation among lignin fragments during heat treatment. ATR-FTIR spectroscopy, thioacidolysis, and 2D HSQC NMR demonstrated that a structural rearrangement occurs in the heat-treated GL400 samples, in which the content of α–PEG-β–O-4 linkages decreases along with the proportional enrichments of β–5 and β–β linkages, particularly at treatment temperatures above 160 °C.

scholarly journals Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties

2021 ◽  
Author(s):  
Giuseppe Del Guercio ◽  
Manuela Galati ◽  
Abdollah Saboori
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Industrial Applications ◽  
Heat Treatments ◽  
Layer By Layer ◽  
Lattice Structures ◽  
Heat Treated ◽  
Aided Design

Abstract Additive Manufacturing processes are considered advanced manufacturing methods. It would be possible to produce complex shape components from a Computer-Aided Design model in a layer-by-layer manner. Lattice structures as one of the complex geometries could attract lots of attention for both medical and industrial applications. In these structures, besides cell size and cell type, the microstructure of lattice structures can play a key role in these structures' mechanical performance. On the other hand, heat treatment has a significant influence on the mechanical properties of the material. Therefore, in this work, the effect of the heat treatments on the microstructure and mechanical behaviour of Ti-6Al-4V lattice structures manufactured by EBM was analyzed. The main mechanical properties were compared with the Ashby and Gibson model. It is very interesting to notice that a more homogeneous failure mode was found for the heat-treated samples. The structures' relative density was the main factor influencing their mechanical performance of the heat-treated samples. It is also found that the heat treatments were able to preserve the stiffness and the compressive strength of the lattice structures. Besides, an increment of both the elongation at failure and the absorbed energy was obtained after the heat treatments. Microstructure analysis of the heat-treated samples confirms the increment of ductility of the heat-treated samples with respect to the as-built one.

Combined treatment of green pitch pine wood by heat and superheated steam and the effects on physical properties of the products

Holzforschung ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Yonggun Park ◽  
Chang-Deuk Eom ◽  
Yeonjung Han ◽  
Jun-Ho Park ◽  
Yoon-Seong Chang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Physical Properties ◽  
Large Scale ◽  
Superheated Steam ◽  
Bending Strength ◽  
Combined Treatment ◽  
Decay Resistance ◽  
Green Wood ◽  
Heat Treated ◽  
Pitch Pine

Abstract Pitch pine (P. rigida) wood was treated with superheated steam (SHS) and the subsequent effects due to drying and heat treatment (HT) were observed. The following treatment parameters were tested: 180°C air HT, 220°C air HT, 0.1 MPa–180°C SHS HT, 0.1 MPa–220°C SHS HT, 0.5 MPa–180°C SHS HT, and 0.5 MPa–220°C SHS HT. No drying checks were observed in the specimens (500×150×50 mm3) treated at 0.5 MPa–220°C SHS and with these treatment parameters, equilibrium moisture content (EMC) was the lowest. Low EMC has an effect on physical properties such as shrinkage, compressive strength parallel to the grain, bending strength, hardness, and decay resistance. Based on the results, it is expected that the green wood in a large scale is possible to be simultaneously dried and heat-treated without occurrence of checks by the SHS HT process.

scholarly journals Calorific Power Improvement of Wood by Heat Treatment and Its Relation to Chemical Composition

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5322
Author(s):  
Idalina Domingos ◽  
Umit Ayata ◽  
José Ferreira ◽  
Luisa Cruz-Lopes ◽  
Ali Sen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Lignin Content ◽  
Treated Wood ◽  
Untreated Wood ◽  
High Heating Value ◽  
Heat Treated ◽  
Positive Linear Correlation ◽  
Total Extractives ◽  
Calorific Power

Chemical composition influences the calorific power of wood, mainly due to the calorific power of structural compounds and extractives. Heat treatment changes the chemical composition of treated wood. This work studies the relationship between chemical composition and calorific power improvement by heat treatment. Samples were heat-treated by the ThermoWood process ® for 1 h and 2 h. High heating value (HHV) and chemical composition; lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol, and water were determined. The HHV of untreated wood ranged between 18.54–19.92 MJ/kg and increased with heat treatment for all the tested species. A positive linear correlation was found between HHV and Klason lignin (R2 = 0.60). A negative trend was observed for holocellulose, cellulose, and hemicelluloses content against HHV, but with low determination coefficients for linear regression. The best adjust for polysaccharides was found for hemicelluloses content. A positive correlation could be found for dichloromethane extractives (R2 = 0.04). The same was obtained in relation to ethanol extractives with R2 = 0.20. For water and total extractives, no clear positive or negative trends could be achieved. The results showed that the HHV of wood increased with heat treatment and that this increase was mainly due to the increase in lignin content.

scholarly journals Comparison of colors, microstructure, chemical composition and thermal properties of bamboo fibers and parenchyma cells with heat treatment

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Jieyu Wu ◽  
Tuhua Zhong ◽  
Wenfu Zhang ◽  
Jiangjing Shi ◽  
Benhua Fei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Chemical Composition ◽  
Lignin Content ◽  
Treatment Temperature ◽  
Composition Analysis ◽  
Chemical Compositions ◽  
Cellulose Content ◽  
Parenchyma Cells ◽  
Bamboo Fibers

AbstractThe effects of heat treatment at various temperatures on mechanically separated bamboo fibers and parenchyma cells were examined in terms of color, microstructure, chemical composition, crystallinity, and thermal properties. The heat-treated parenchyma cells and fibers were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), chemical composition analysis, and thermogravimetric analysis (TGA). The results revealed that the colors of bamboo fibers and parenchyma cells were darkened as treatment temperature increased. The microstructure of the treated fibers and parenchyma cells slightly changed, yet the shape of starch granules in parenchyma cells markedly altered at a temperature of above 160 °C. The chemical compositions varied depending on the heat treatment temperature. When treated at 220 °C, the cellulose content was almost unchanged in fibers but increased by 15% in parenchyma cells; the hemicellulose content decreased and the lignin content increased regardless of fibers and parenchyma cells. The cellulose crystal structure was nearly unaffected by heat treatment, but the cellulose crystallinity of fibers changed more pronouncedly than that of parenchyma cells. The thermal stability of parenchyma cells after heat treatment was affected more substantially compared to fibers.

scholarly journals Heat Treatment Effect on the Surface Properties of Carbon Cloth Electrode for Microbial Fuel Cell

2021 ◽  
pp. X
Author(s):  
Shih-Hang CHANG ◽  
Yuan-Ting TSAO ◽  
Kuan-Wei TUNG
Keyword(s):  
Heat Treatment ◽  
Surface Properties ◽  
Microbial Fuel Cells ◽  
Large Scale ◽  
Carbon Cloth ◽  
Water Contact ◽  
Angle Measurements ◽  
Heat Treated ◽  
Contact Angle Measurements ◽  
Treated Carbon

In this study, we investigate the effect of heat treatment on the surface properties of carbon cloth electrodes and on the power generation efficiencies of microbial fuel cells (MFCs) configured with the heat-treated carbon cloth electrodes. Water contact angle measurements show that the hydrophobic surfaces of the carbon cloth became super-hydrophilic after heat treatment at a temperature above 500 °C, making it suitable for bacterial propagation. X-ray photoelectron spectrometry revealed that the signal of the C-O functional group of the carbon cloth electrodes increased in intensity after heat treatment. The MFCs configured with heat-treated carbon cloth electrode exhibited high power density of 16.58 mW/m2, whereas that of the untreated MFCs was only 8.86 mW m2. Compared with other chemical modifications, heat treatment does not use any environmentally unsound acidic or toxic solutions during modification and are promising for manufacturing large-scale MFC stacks.

scholarly journals Effects of Heat Treatment of Selective Laser Melting Printed Ti-6Al-4V Specimens on Surface Texture Parameters and Cell Attachment

2021 ◽  
Vol 11 (5) ◽  
pp. 2234
Author(s):  
Pei-Wen Peng ◽  
Jen-Chang Yang ◽  
Wei-Fang Lee ◽  
Chih-Yuan Fang ◽  
Chun-Ming Chang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Surface Texture ◽  
Large Scale ◽  
Cell Attachment ◽  
Characteristic Length ◽  
Laser Melting ◽  
Heat Treated ◽  
Texture Parameters ◽  
Areal Surface

Selective laser melting (SLM) is extensively used for fabricating metallic biomedical products. After 3D printing, it is almost always advisable to apply a heat treatment to release the internal tensions or optimize the mechanical properties of the printed parts. The aim of this paper is to investigate the effects of heat treatment of SLM printed Ti-6Al-4V (Ti64) circular specimens on the areal surface texture parameters and cell attachment. Areal surface texture parameters, including the arithmetic mean height (Sa), root-mean-square height (Sq), skewness (Ssk), and kurtosis (Sku) were characterized. In addition, wavelet-based multi-resolution analysis was applied to investigate the characteristic length scales of untreated and heat-treated Ti64 specimens. In this study, the vertical distance between the highest and lowest position of cell attachment for each sampling area was defined as DH. Results showed that an increase in the periodic characteristic length scale was primarily due to the formation of large-scale aggregations of Ti64 metal powder particles on the heat-treated surface. In addition, MG-63 cells preferred lying in concave hollows; in heat-treated specimens, values of DH statistically significantly decreased from 31.6 ± 4.2 to 8.8 ± 2.8 μm, while Sku decreased from 3.3 ± 1.4 to 2.6 ± 0.6, indicating a strong influence of Sku on cell attachment.

Strength properties and dimensional stability of particleboards with different proportions of thermally treated recycled pine particles

Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Paulo Ivan Andrade ◽  
Solange de Oliveira Araújo ◽  
Duarte Miranda Neiva ◽  
Benedito Rocha Vital ◽  
Angélica de Cássia Oliveira Carneiro ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Dimensional Stability ◽  
Lignin Content ◽  
Strength Properties ◽  
Raw Material ◽  
Heat Treated ◽  
Wood Particles ◽  
Partial Degradation ◽  
Thermal Stability Of

Abstract Wood-based panels made of waste and recycled raw material are lacking of dimensional stability. The aim of this study is to evaluate the potential beneficial effect of heat treatment (HT) on the properties of particleboards produced from waste of Pinus sp. used for packaging. The wood particles were heat treated at 180°C, 200°C and 220°C after grinding, and panels were produced with incorporation of 25%, 50%, 75% and 100% HT particles. The materials served as reference were particles without HT. Mass loss at 180°C and 200°C was small but increased significantly to 10.6% at 220°C. The HT caused a partial degradation of hemicelluloses, thereby the relative lignin content increased from 29.7% to 37.8% for the HT220°C samples. Thermogravimetry revealed higher thermal stability of the HT particles. The equilibrium moisture content decreased with HT, e.g. panels with HT220°C showed 30% lower compared to the reference. Swelling of the panels was lowered by 30% (panel with 75% HT material) compared to the reference. The results with HT pine were successful in terms of dimensional stability and lower hygroscopicity; however, the panels lost some strength properties.

scholarly journals EFFECTS OF HEAT TREATMENT ON SOME CHEMICAL COMPOUND AND MECHANICAL PROPERTIES OF BLACK PINE WOOD

Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 621-629
Author(s):  
SAHIN AKYUREK ◽  
MURAT AKMAN ◽  
MURAT OZALP
Keyword(s):  
Heat Treatment ◽  
Compression Strength ◽  
Chemical Compound ◽  
Bending Strength ◽  
Lignin Content ◽  
Pinus Nigra ◽  
Black Pine ◽  
Pine Wood ◽  
Heat Treated ◽  
And Control

In this study, effects of heat treatment on bending strength, compression strength, chemical compound and solubility of Black pine wood (Pinus nigra J.F.var. seneriana)was examined.For this purpose, Black pine wood samples were kept in temperature of 250°C for 2 hours. Test results of heat-treated Black pine wood and control samples indicated that mechanical characteristics including compression strength and bending strength were affected negatively with heat treatment. Bending strength of heat treated and non-treated test samples were 129 and 76 N.mm-2, respectively. Compression strength of heat treated and non-treated test samples were 53 and 43N.mm-2, resp.In addition, level of extractives, cellulose and hemicellulose decreased while lignin content increased with percentage of 40%. Significant decreases occurred in all chemical solubility values.

Thermal Properties of the Polyolefin Based Elastic Filament DOW XLATM

2012 ◽  
Vol 627 ◽  
pp. 143-146
Author(s):  
Ni Wang ◽  
Zhao Lin Liu ◽  
Xi Ting Chen
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Loss Rate ◽  
Elastic Recovery ◽  
Treatment Temperature ◽  
Scanning Calorimetry ◽  
Weight Loss Rate ◽  
Highest Weight ◽  
Heat Treated ◽  
Elastic Filament

Thermal properties of the elastic filament DOW XLATMwere analyzed by differential scanning calorimetry (DSC) and thermogravimetry analysis (TG). Besides, the elastic recovery characteristics after heat treatment were also discussed. The DSC scan shows typical endotherms and its melting temperature (Tm) ranges from 28 °C- 65 °C. TG analysis indicates that the thermal degradation begins at 285 °C and the highest weight loss rate occurs at 461.9 oC. When the filaments are heat treated under relaxation or at constant elongatiSuperscript texton, their elastic recovery ratios all decrease with the increase of the heat treatment temperature except for 50 °C.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

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