scholarly journals Fique as a Sustainable Material and Thermal Insulation for Buildings: Study of Its Decomposition and Thermal Conductivity

2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano
Keyword(s):  
Thermal Conductivity ◽  
Thermal Decomposition ◽  
Thermal Insulation ◽  
Model Fitting ◽  
Good Alternative ◽  
Negative Effects ◽  
Thermal Insulator ◽  
Fitting Method ◽  
Thermogravimetric Data ◽  
Reduce Energy Consumption

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.

scholarly journals Structure, Mechanism, and Application of Vacuum Insulation Panels in Chinese Buildings

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Changhai Peng ◽  
Jianqiang Yang
Keyword(s):  
Thermal Conductivity ◽  
Construction Industry ◽  
Thermal Insulation ◽  
Fire Resistance ◽  
New Materials ◽  
Insulation Materials ◽  
Vacuum Insulation ◽  
Application Potential ◽  
Reduce Energy Consumption ◽  
Sealing Layer

Thermal insulation is one of the most used approaches to reduce energy consumption in buildings. Vacuum insulation panels (VIPs) are new thermal insulation materials that have been used in the domestic and overseas market in the last 20 years. Due to the vacuum thermal insulation technology of these new materials, their thermal conductivity can be as low as 0.004 W/(m·K) at the center of panels. In addition, VIPs that are composites with inorganic core and an envelope out of commonly three metallized PET layers and a PE sealing layer can provide B class fire resistance (their core materials are not flammable and are classified as A1). Compared with other conventional thermal insulation materials, the thermal insulation and fire resistance performances form the foundation of VIP’s applications in the construction industry. The structure and thermal insulation mechanism of VIP and their application potential and problems in Chinese buildings are described in detail.

An ultralow-temperature superelastic polymer aerogel with high strength as a great thermal insulator under extreme conditions

2020 ◽  
Vol 8 (36) ◽  
pp. 18698-18706
Author(s):  
Ting Wang ◽  
Man-Cheng Long ◽  
Hai-Bo Zhao ◽  
Bo-Wen Liu ◽  
Hai-Gang Shi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Flame Retardancy ◽  
High Strength ◽  
Extreme Conditions ◽  
Thermal Insulator ◽  
Ultralow Temperature ◽  
Polymer Aerogel ◽  
And Performance ◽  
Harsh Conditions

Taking advantage of structural elastic strategy to create polymer aerogels with ultralow-temperature superelasticity. The aerogels also display low thermal conductivity, excellent thermal insulation under harsh conditions, flame retardancy, and performance stability.

scholarly journals Utilization of Water Hyacinth (Eichhornia crassipes) and Corncob (Zea mays) in Epoxy-based Biocomposite Board for Cool Box Thermal Insulation Material

2021 ◽  
Vol 891 (1) ◽  
pp. 012001
Author(s):  
N M K S Sruti ◽  
P R Jenaneswari ◽  
M R Rahayu ◽  
FA Syamani
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Bending Strength ◽  
Insulation Material ◽  
Thermal Insulation Material ◽  
Thermal Insulator ◽  
Useful Life ◽  
Effectiveness Assessment

Abstract Generally, the cool box is produced using styrofoam as the main thermal insulation material. However, the use of styrofoam potentially cause pollution to the environment at the end of its useful life because it cannot decompose naturally. The effort to overcome this problem is by producing thermal insulation materials from natural sources such as water hyacinth and corncob. The purpose of this study was to determine the characteristics of biocomposite board made from combination of water hyacinth powder and corncob ash based on physical, mechanical, and thermal conductivity analysis. Biocomposite boards were produced by introducing combination of water hyacinth powder and corncorb ash (5, 10, 15%wt) into epoxy resin. The ratio of water hyacinth powder and corncob ash were 100:0 (P0), 95:5 (P1), 90:10 (P2), 85:15 (P3). The biocomposite boards were also made from water hyacinth powder and corncob powder, which ratio of 15:85 (P4) and 0:100 (P5). The results of this research revealed that type P5 board had the lowest density value (0.927 g / cm3) and the lowest water absorption value (1.53%). The P2 type board shows the highest bending strength (8.6 N/mm2) which met the requirements of JIS A 5908 for particleboards type 8. The highest value of compressive strength was observed at P5 type board which was 2.94 ± 0.53 N / mm2. The lowest thermal conductivity values were observed at P2 type boards (0.305 W / mK). It can be concluded that, P2 type board had the best thermal insulator properties among other boards in this study. The thermal insulation effectiveness assessment of biocomposite board for cool box application was conducted using P2 and P5 type boards. The assessment results demonstrated that the styrofoam cool box and commercial cool box performance for maintaining temperature were superior compared to biocomposite cool box. Therefore, it is necessary to re-examine the biocomposite cool box, especially in terms of panel assembling and the shape of the lid, to produce biocomposite cool box with thermal insulator properties comparable to the commercial cool box.

scholarly journals Microstructure Dependence of Effective Thermal Conductivity of EB-PVD TBCs

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1838
Author(s):  
Shi-Yi Qiu ◽  
Chen-Wu Wu ◽  
Chen-Guang Huang ◽  
Yue Ma ◽  
Hong-Bo Guo
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Stress ◽  
Effective Thermal Conductivity ◽  
Thermal Insulation ◽  
Inclination Angle ◽  
Physical Vapor Deposition ◽  
Thermal Contact ◽  
Mathematic Model ◽  
Columnar Structure ◽  
Structural Parameter

Microstructure dependence of effective thermal conductivity of the coating was investigated to optimize the thermal insulation of columnar structure electron beam physical vapor deposition (EB-PVD coating), considering constraints by mechanical stress. First, a three-dimensional finite element model of multiple columnar structure was established to involve thermal contact resistance across the interfaces between the adjacent columnar structures. Then, the mathematical formula of each structural parameter was derived to demonstrate the numerical outcome and predict the effective thermal conductivity. After that, the heat conduction characteristics of the columnar structured coating was analyzed to reveal the dependence of the effective thermal conductivity of the thermal barrier coatings (TBCs) on its microstructure characteristics, including the column diameter, the thickness of coating, the ratio of the height of fine column to coarse column and the inclination angle of columns. Finally, the influence of each microstructural parameter on the mechanical stress of the TBCs was studied by a mathematic model, and the optimization of the inclination angle was proposed, considering the thermal insulation and mechanical stress of the coating.

Bio-based Polyurethane-clay Nanocomposite Foams: Systheses and Properties

2009 ◽  
Vol 1188 ◽  
Author(s):  
Min Liu ◽  
Zoran S. Petrovic ◽  
Yijin Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Cell Content ◽  
Modified Clay ◽  
Rigid Polyurethane Foams ◽  
Nanocomposite Foams ◽  
Organically Modified

AbstractStarting from a bio-based polyol through modification of soybean oil, BIOH™ X-210, two series of bio-based polyurethanes-clay nanocomposite foams have been prepared. The effects of organically-modified clay types and loadings on foam morphology, cell structure, and the mechanical and thermal properties of these bio-based polyurethanes-clay nanocomposite foams have been studied with optical microscopy, compression test, thermal conductivity, DMA and TGA characterization. Density of nanocomposite foams decreases with the increase of clay loadings, while reduced 10% compressive stress and yield stress keep constant up to 2.5% clay loading in polyol. The friability of rigid polyurethane-clay nanocomposite foams is high than that of foam without clay, and the friability for nanofoams from Cloisite® 10A is higher than that from 30B at the same clay loadings. The incorporation of clay nanoplatelets decreases the cell size in nanocomposite foams, meanwhile increases the cell density; which would be helpful in terms of improving thermal insulation properties. All the nanocomposite foams were characterized by increased closed cell content compared with the control foam from X-210 without clay, suggesting the potential to improve thermal insulation of rigid polyurethane foams by utilizing organically modified clay. Incorporation of clay into rigid polyurethane foams results in the increase in glass transition temperature: the Tg increased from 186 to 197 to 204 °C when 30B concentration in X-210 increased from 0 to 0.5 to 2.5%, respectively. Even though the thermal conductivity of nanocomposite foams from 30B is lower than or equal to that of rigid polyurethane control foam from X-210, thermal conductivity of nanocomposite foams from 10A is higher than that of control at all 10A concentrations. The reason for this abnormal phenomenon is not clear at this moment; investigation on this is on progress.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Development and Research of Thermal Insulation Materials from Natural Fibres

2014 ◽  
Vol 604 ◽  
pp. 285-288 ◽  
Author(s):  
Saulius Vaitkus ◽  
Rūta Karpavičiūtė ◽  
Sigitas Vėjelis ◽  
Lina Lekūnaitė
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Preparation Method ◽  
Raw Materials ◽  
Natural Fibres ◽  
Current Work ◽  
Insulation Materials ◽  
Flax Fibres ◽  
Hemp Fibres

Natural fibres from flax and hemp are used as raw materials for efficient thermal insulation. In current work, tests were carried out using chopped and combed long flax fibres as well as chopped and combed long hemp fibres. Investigations have shown that thermal conductivity of natural fibres depends on their preparation method (combing, chopping) and materials density.

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