scholarly journals Influence of Silica-Aerogel on Mechanical Characteristics of Polyurethane-Based Composites: Thermal Conductivity and Strength

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1790
Author(s):  
Jeong-Hyeon Kim ◽  
Jae-Hyeok Ahn ◽  
Jeong-Dae Kim ◽  
Dong-Ha Lee ◽  
Seul-Kee Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Cell Morphology ◽  
Environmental Conditions ◽  
Silica Aerogel ◽  
Porous Silica ◽  
Mechanical And Thermal Properties ◽  
Insulation Material ◽  
Wide Range ◽  
Insulation Systems

Polyurethane foam (PUF) has generally been used in liquefied natural gas (LNG) carrier cargo containment systems (CCSs) owing to its excellent mechanical and thermal properties over a wide range of temperatures. An LNG CCS must be designed to withstand extreme environmental conditions. However, as the insulation material for LNGC CCSs, PUF has two major limitations: its strength and thermal conductivity. In the present study, PUFs were synthesized with various weight percentages of porous silica aerogel to reinforce the characteristics of PUF used in LNG carrier insulation systems. To evaluate the mechanical strength of the PUF-silica aerogel composites considering LNG loading/unloading environmental conditions, compressive tests were conducted at room temperature (20 °C) and a cryogenic temperature (−163 °C). In addition, the thermal insulation performance and cellular structure were identified to analyze the effects of silica aerogels on cell morphology. The cell morphology of PUF-silica aerogel composites was relatively homogeneous, and the cell shape remained closed at 1 wt.% in comparison to the other concentrations. As a result, the mechanical and thermal properties were significantly improved by the addition of 1 wt.% silica aerogel to the PUF. The mechanical properties were reduced by increasing the silica aerogel content to 3 wt.% and 5 wt.%, mainly because of the pores generated on the surface of the composites.

Mechanical and thermal properties of reticulated SiC aerogel composite prepared by template method

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4117-4124
Author(s):  
Xinli Ye ◽  
Zhaofeng Chen ◽  
Sufen Ai ◽  
Junxiong Zhang ◽  
Bin Hou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Silica Aerogel ◽  
Sol Gel ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Template Method ◽  
Mechanical And Thermal Properties ◽  
Insulation Material ◽  
Aerogel Composite

A novel structure-controllable reticulated silicon carbide (SiC) skeleton-reinforced silica aerogel composites (SiC/aerogel) were fabricated successfully by template method. Three-dimensional SiC skeletons prepared by different deposition time were prepared via the chemical vapor deposition technology, and then the silica aerogel was induced by the sol–gel process. The test results showed that the mechanical properties increased and thermal conductivities decreased remarkably after impregnating reticulated SiC skeleton with silica aerogel. The SiC/aerogel-24 possessed the highest compressive strength of 0.82 MPa with the thermal conductivity of 0.1597 W/(m·K) at 600℃, while the SiC/aerogel-12 exhibited the lowest thermal conductivity of 0.1244 W/(m·K) and its compressive strength was 0.64 MPa. The present work reported a novel method to manufacture the structure-controllable reticulated SiC aerogel composite which could be used as a high-temperature super-thermal insulation material for the potential applications.

Preparative Techniques and its Performance of Chemically Foamed Cement Paste

2013 ◽  
Vol 690-693 ◽  
pp. 700-703
Author(s):  
Xin Wei Ma ◽  
Xue Ying Li
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Bulk Density ◽  
Cement Paste ◽  
Expanded Polystyrene ◽  
Mechanical And Thermal Properties ◽  
Insulation Material ◽  
Light Weight ◽  
Preparation Process ◽  
Composite Walls

The foamed cement paste (FCP) is a kind of inorganic insulation material. It is characterized by its light weight, heat-insulating and fire-proofing properties, and the thermal conductivity is close to that of expanded polystyrene (EPS). The foamed cement paste is achieved by means of chemical reaction. The mixture proportion, the preparation process, mechanical and thermal properties are investigated in this paper. The results show that properly mixed paste foams stably, and the bulk density could be controlled. The hardened FCP could be used as insulating filler material in composite walls, as well as blocks for Thermal insulation walls.

Studies on Thermal Property of Silica Aerogel/Epoxy Composite

2007 ◽  
Vol 546-549 ◽  
pp. 1581-1584 ◽  
Author(s):  
Jiu Peng Zhao ◽  
Deng Teng Ge ◽  
Sai Lei Zhang ◽  
Xi Long Wei
Keyword(s):  
Thermal Conductivity ◽  
Thermal Property ◽  
Epoxy Resin ◽  
Silica Aerogel ◽  
Epoxy Composite ◽  
Transfer Model ◽  
Insulation Material ◽  
Thermal Transfer ◽  
Heat Distortion Temperature ◽  
Ft Ir

Silica aerogel/epoxy composite, a kind of efficient thermal insulation material, was prepared by doping silica aerogel of different sizes into epoxy resin through thermocuring process. The results of thermal experiments showed that silica aerogel/epoxy composite had a lower thermal conductivity (0.105W/(m·k) at 60 wt% silica aerogel) and higher serviceability temperature (Martens heat distortion temperature: 160°C at 20 wt% silica aerogel). In addition, the composite doping larger size (0.2-2mm) of silica aerogel particle had lower thermal conductivity and higher Martens heat distortion temperature. Based on the results of SEM and FT-IR, the thermal transfer model was established. Thermal transfer mechanism and the reasons of higher Martens heat distortion temperature have been discussed respectively.

Mechanical and Thermal Properties of Magnesia Binder Based on Natural and Technogenic Raw Materials

2021 ◽  
Vol 320 ◽  
pp. 181-185
Author(s):  
Elvija Namsone ◽  
Genadijs Sahmenko ◽  
Irina Shvetsova ◽  
Aleksandrs Korjakins
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Raw Materials ◽  
High Strength ◽  
Strength Properties ◽  
Waste Materials ◽  
Mechanical And Thermal Properties ◽  
Experimental Part ◽  
Technogenic Raw Materials ◽  
Caustic Magnesia

Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.

scholarly journals Experimental investigation of rockwool insulation hygrothermal properties related to material structure

2015 ◽  
Vol 19 (3) ◽  
pp. 923-928 ◽  
Author(s):  
Maja Djurovic-Petrovic
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Sorption Properties ◽  
Material Structure ◽  
Insulation Material ◽  
Wide Range ◽  
Two Samples

The hygrothermal properties related to rockwool insulation material structure with different additives are presented using rockwool insulation products obtained from row material of southern Serbia (Vranje region) in the wide range of reference temperatures (10?C to 70?C). The hygrothermal properties of basic sample (without additives) are compared to two samples with different additives for two sets of rockwool insulation samples namely: light-soft-panels (LSP) with density of 50 kg/m3, and middle-weight-panels (MWP) with density of 80 kg/m3. It is shown that there is significant (approximately 10%) improvement of thermal conductivity for additives based on zeolite. Also, correlation of thermal conductivity and sorption properties of selected samples are presented.

scholarly journals Bio-based rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application – Part 2: Morphological, mechanical, and thermal properties

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6080-6094
Author(s):  
Muhammed Said Fidan ◽  
Murat Ertaş
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Polyurethane Foam ◽  
Flame Retardants ◽  
Compressive Modulus ◽  
Cell Diameter ◽  
Mechanical And Thermal Properties ◽  
Rigid Polyurethane Foam

The procedure for the liquefaction of apricot stone shells was reported in Part 1. Part 2 of this work determines the morphological, mechanical, and thermal properties of the bio-based rigid polyurethane foam composites (RPUFc). In this study, the thermal conductivity, compressive strength, compressive modulus, thermogravimetric analysis, flammability tests (horizontal burning and limited oxygen index (LOI)) in the flame retardants), and scanning electron microscope (SEM) (cell diameter in the SEM) tests of the RPUFc were performed and compared with control samples. The results showed the thermal conductivity (0.0342 to 0.0362 mW/mK), compressive strength (10.5 to 14.9 kPa), compressive modulus (179.9 to 180.3 kPa), decomposition and residue in the thermogravimetric analysis (230 to 491 °C, 15.31 to 21.61%), UL-94 and LOI in the flame retardants (539.5 to 591.1 mm/min, 17.8 to 18.5%), and cell diameter in the SEM (50.6 to 347.5 μm) of RPUFc attained from liquefied biomass. The results were similar to those of foams obtained from industrial RPUFs, and demonstrated that bio-based RPUFc obtained from liquefied apricot stone shells could be used as a reinforcement filler in the preparation of RPUFs, specifically in construction and insulation materials. Moreover, liquefied apricot stone shell products have potential to be fabricated into rigid polyurethane foam composites.

Mechanical and thermal properties of nanofibrillated cellulose reinforced silica aerogel composites

2015 ◽  
Vol 217 ◽  
pp. 150-158 ◽  
Author(s):  
Joanna C.H. Wong ◽  
Hicret Kaymak ◽  
Philippe Tingaut ◽  
Samuel Brunner ◽  
Matthias M. Koebel
Keyword(s):  
Thermal Properties ◽  
Silica Aerogel ◽  
Nanofibrillated Cellulose ◽  
Mechanical And Thermal Properties

Research on Heat Transfer Characteristics of Nano-Porous Silica Aerogel Material and its Application on Mars Surface Mission

2014 ◽  
Vol 924 ◽  
pp. 329-335 ◽  
Author(s):  
Cong Hang Li ◽  
Shi Chen Jiang ◽  
Zheng Ping Yao ◽  
Song Sheng ◽  
Xin Jian Jiang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Thermal Environment ◽  
Porous Silica ◽  
Heat Transfer Model ◽  
Heat Radiation ◽  
Transfer Model ◽  
Ambient Conditions ◽  
Coupled Heat Transfer

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.

Thermographic Studies of Aerogel Composites

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
K. Keerthi Sanghamitra ◽  
A. Yamini ◽  
A. Venu Vinod ◽  
Neha Hebalkar
Keyword(s):  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Cold Water ◽  
High Porosity ◽  
Fiber Mats ◽  
Aerospace Applications ◽  
Thermal Insulating ◽  
Wide Range ◽  
Composite Form ◽  
Insulation Performance

AbstractAerogels are regarded as the superior thermal insulating materials for wide range of temperatures, from cryogenic insulation, cold water diving garments to high temperature applications and even to defense and aerospace applications. For most of such applications, the aerogels are used in composite form rather than monolithic form as aerogels are fragile in nature due to its high porosity of up to 98%. These composites constitute aerogel infiltrated fiber mats to give flexibility, on the other hand, compromises on the insulation performance due to reinforcing aerogel with fibers that have comparatively higher thermal conductivity than silica aerogel. To increase the efficiency, density of the fiber mat needs to be reduced to incorporate higher loading of silica aerogel. Many techniques are being used to study the insulation performance of these composites. This paper presents about the study of insulation performance of fibre mats with different aerogel content and composition using a well-known thermography technique. The morphological, compositional, thermal and physical studies of the fiber mats and its composites using FESEM, EDAX, BET, thermal conductivity etc., are discussed.

Enhancement of Mechanical and Thermal Characteristics of Polyurethane-Based Composite with Silica Aerogel

2019 ◽  
Vol 951 ◽  
pp. 63-67 ◽  
Author(s):  
Jae Hyeok Ahn ◽  
Jeong Hyeon Kim ◽  
Jeong Dae Kim ◽  
Seul Kee Kim ◽  
Kang Hyun Park ◽  
...  
Keyword(s):  
Silica Aerogel ◽  
Heat Insulation ◽  
Porous Silica ◽  
Thermal Characteristics ◽  
Weight Percent ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Efficient Alternative ◽  
Insulation Performance ◽  
Compressive Tests

Synthesis of polyurethane foams (PUF) with silica aerogel nanoparticles is an efficient alternative to improve the mechanical and thermal properties of the foam owing to the outstanding thermal insulation properties of porous silica aerogel nanoparticles. Silica aerogel was added into polyurethane foams at different weight percent (0, 1, 3, 5 wt.%) to observe the changes in the material properties. To confirm the applicability of the synthesized PUF to the heat insulating material, compressive tests were carried out at ambient and cryogenic temperature (20, -163°C) and the thermal conductivities were measured according to wt.%. In addition, the cell microstructure was identified using FE-SEM to analyze the effect of silica aerogels on the foam morphologies. As a result of the experiment, it was confirmed that the mechanical strength and the heat insulation performance were improved in the polyurethane foam containing 1 wt.% of silica aerogel.

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