scholarly journals Effect of Granular Silica Aerogel as Filler on Tensile and Flexural Strengths and Moduli of Stone-Wool-Fibre-Reinforced Composite as Rigid Board Roof Insulation Material

2021 ◽  
Vol 945 (1) ◽  
pp. 012061
Author(s):  
Nadzhratul Husna ◽  
Syed Ahmad Farhan ◽  
Mohamed Mubarak Abdul Wahab ◽  
Mohamed Mubarak Abdul Wahab ◽  
Nasir Shafiq ◽  
...  

Abstract Installation of stone wool as thermal insulation in the roof assembly can be adopted to store heat in the living space, if the building is exposed to cold weather, and, inversely, to retard heat from entering the living space, if it is exposed to hot weather. In spite of the effectiveness of stone wool as a roof insulation material, during installation, it can cause irritation to the skin and can be hazardous to the lungs. Therefore, incorporation of stone wool with other materials to form a rigid board, without compromising its effectiveness as a roof insulation material, is imperative. Strength properties of a stone-wool-fibre-reinforced high-density polyethylene (HDPE) composite roof insulation material were studied. Granular silica aerogel, which possesses an ultra-low thermal conductivity, was added as filler to reduce the thermal conductivity of the composite. Hot compression moulding was performed to prepare samples of the composite with varying silica aerogel content of 0, 1, 2, 3, 4, and 5 wt. %. Findings suggest that 2 wt.% is the optimum silica aerogel content as it resulted in the highest flexural strength and modulus, which is 24.4 MPa and 845.85 MPa, respectively, even though it reduced the tensile strength and modulus by 10% and 4.45% respectively, relative to 0 wt. %, which can be considered as inconsequential. Higher silica aerogel content above 2 wt. % may result in poor interfacial adhesion and low compatibility to the stone wool fibre and HDPE, which further reduces the tensile and flexural strengths and moduli of the composite.

2007 ◽  
Vol 546-549 ◽  
pp. 1581-1584 ◽  
Author(s):  
Jiu Peng Zhao ◽  
Deng Teng Ge ◽  
Sai Lei Zhang ◽  
Xi Long Wei

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.


2019 ◽  
Vol 53 (28-30) ◽  
pp. 4117-4124
Author(s):  
Xinli Ye ◽  
Zhaofeng Chen ◽  
Sufen Ai ◽  
Junxiong Zhang ◽  
Bin Hou ◽  
...  

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.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2140
Author(s):  
Guangxu Bo ◽  
Xiaoling Xu ◽  
Xiaoke Tian ◽  
Jiao Wu ◽  
Yunjun Yan

Rigid polyurethane foams (RPUFs) are widely used in many fields, but they are easy to burn and produce a lot of smoke, which seriously endangers the safety of people’s lives and property. In this study, tetraethyl(1,5–bis(bis(2–hydroxypropyl)amino)pentane–1,5–diyl)bis(phosphonate) (TBPBP), as a phosphorus–nitrogen–containing reactive–type flame retardant, was successfully synthesized and employed to enhance the flame retardancy of RPUFs, and silica aerogel (SA) powder was utilized to reduce harmful fumes. Castor oil–based rigid polyurethane foam containing SA powder and TBPBP was named RPUF–T45@SA20. Compared with neat RPUF, the obtained RPUF–T45@SA20 greatly improved with the compressive strength properties and the LOI value increased by 93.64% and 44.27%, respectively, and reached the V–0 rank of UL–94 testing. The total heat release (THR) and total smoke production (TSP) of RPUF–T45@SA20 were, respectively, reduced by 44.66% and 51.89% compared to those of the neat RPUF. A possible flame–retardant mechanism of RPUF–T45@SA20 was also proposed. This study suggested that RPUF incorporated with TBPBP and SA powder is a prosperous potential composite for fire and smoke safety as a building insulation material.


2021 ◽  
Vol 945 (1) ◽  
pp. 012066
Author(s):  
Nadzhratul Husna ◽  
Syed Ahmad Farhan ◽  
Mohamed Mubarak Abdul Wahab ◽  
Nasir Shafiq ◽  
Muhammad Taufiq Sharif ◽  
...  

Abstract Malaysia is located in the equator, with a hot and humid climate. The highest temperature recorded during the day was 39 °C, which leads to discomfort among building occupants, in particular, residential buildings, where indoor thermal comfort is of a higher priority compared to other types of buildings. Hence, the thermal performance of the residential roof assembly needs to be improved to lower the indoor temperature and, accordingly, maintain the level of indoor thermal comfort. In view of the need to improve the thermal performance, a silica-aerogel-incorporated rigid board roof insulation material for residential buildings was developed using kapok fibre, high density polyethylene (HDPE) and silica aerogel. The thermal conductivity of the material was measured. The sample with 4 wt. % and 5 wt. % of silica aerogel content obtained the lowest thermal conductivity of 0.04 W/mK. Silica aerogel content of above 4 wt. % did not result in further reduction of the thermal conductivity. Therefore, it can be concluded that the optimum silica aerogel content for the sample was 4 wt. %. Building-Information-Modelling (BIM)based thermal-energy performance evaluation of the material was performed by generating temperature and cooling load data using Integrated Environmental Solution-Virtual Environment to validate the thermal-energy performance of the material, by installing the material within the roof assembly of a residential BIM. Findings indicate that the material can potentially be employed in the future as a roof insulation material to maintain the level of indoor thermal comfort among residential building occupants.


2020 ◽  
Vol 845 ◽  
pp. 33-38
Author(s):  
Li Jun Su ◽  
Hui Guo ◽  
Han Song ◽  
Rui Jie Wang ◽  
Wen Jing Li

As its much lower thermal conductivity than other usual materials, Silica aerogel is a potentially efficient heat insulation material with the lowest bulk density. However, it is transparent for infrared light when used in high temperature. Herein, titanium oxide was added in the silica aerogel by in-situ blending. The dispersion property of titanium oxide particles, microstructure mechanical property, thermal conductivity, and thermal insulation were investigated. The results of this in-situ blending process indicated a potential application value in aerospace thermal protection industry.


2020 ◽  
Vol 1007 ◽  
pp. 118-124
Author(s):  
Wen Yi Wang ◽  
Kwok Tung Hui ◽  
Chi Wai Kan ◽  
Krailerck Visesphan ◽  
Saowanee Areechongchareon ◽  
...  

Socks fabrics seem a minor clothing in apparel categories but are indispensable item for daily activities for users. The function of socks is either for heat insulation of body temperature in cold weather or heat releasing to keep thermal neutral for foot in hot weather. Socks with good quality are conducive to prevent foot disease or smelly odor from foot. The wearing comfort of socks can be affected by the fabric properties of thermal transfer. The present study aims to investigate the relationship between the fabric parameters and thermal conductivity property of knitted socks fabric. The physical test on commercial socks fabric was carried out in standard condition atmosphere. It was found that the thermal conductivity of fabric was positively proportional to yarn count and thickness.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3983
Author(s):  
Dongxuan Du ◽  
Fengqi Liu ◽  
Yonggang Jiang ◽  
Junzong Feng ◽  
Liangjun Li ◽  
...  

To further reduce the manufacturing cost and improve safety, silica aerogel composites (SAC) with low density and low thermal conductivity synthesized via ambient pressure drying (APD) technology have gradually become one of the most focused research areas. As a solvent, ethanol is flammable and needs to be replaced by other low surface tension solvents, which is dangerous and time-consuming. Therefore, the key steps of solvent replacement and surface modification in the APD process need to be simplified. Here, we demonstrate a facile strategy for preparing high strength mullite fiber reinforced SAC, which is synthesized by APD using water as a solvent, rather than using surface modification or solvent replacement. The effects of the fiber density on the physical properties, mechanical properties, and thermal conductivities of SAC are discussed in detail. The results show that when the fiber density of SAC is 0.24 g/cm3, the thermal conductivity at 1100 °C is 0.127 W/m·K, and the compressive strength at 10% strain is 1.348 MPa. Because of the simple synthesis process and excellent thermal-mechanical performance, the SAC is expected to be used as an efficient and economical insulation material.


2018 ◽  
Vol 25 (6) ◽  
pp. 1107-1114
Author(s):  
Hongyan Li ◽  
Limeng Song ◽  
Cong Sun ◽  
Ruyi Li ◽  
Yongqiang Fu ◽  
...  

AbstractContradictions of strength and thermal insulation of silica aerogel (SA) are of wide concern. In this research, the mesoporous structure of SA was grafted with the polymers to increase the strength of SA and decrease the thermal conductivity of composites. The composites were characterized and analyzed using field emission scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, the thermal gravimetric analyzer (TGA), multi-assay gel permeation chromatography (GPC), a microcomputer control electronic universal testing machine and so on. The results indicated that amino-capped polydivinylsiloxane (AP) was successfully grafted on the SA surface and polymerized with methyl methacrylate (MMA) to form an AP high thermal insulation phase interface between the SA phase and poly(methyl methacrylate) (PMMA) phase. The SA-AP/PMMA composite with a covalent bonding high thermal insulation phase interface had better mechanical properties and compressive strength than those of SA/PMMA. The obtained composite was an excellent thermal insulation material with lower thermal conductivity [0.045 W/(m·K)].


Sign in / Sign up

Export Citation Format

Share Document