Studies of the Influence of Graphite on the Physical Mechanical and Thermal Properties of Polyurethane Foams for Construction Applications

2021 ◽  
Vol 887 ◽  
pp. 399-405
Author(s):  
L.N. Shafigullin ◽  
N.V. Romanova ◽  
G.R. Shafigullina
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Polyurethane Foams ◽  
Onset Temperature ◽  
Sound Absorption Coefficient ◽  
Expandable Graphite ◽  
Mechanical And Thermal Properties ◽  
Pu Foam

The paper shows the applicability of expandable graphite METOPAC EG 350-50 (80) in a rigid PU foam system as a substance that reduces the flammability (flame retardant) and improves the usability. The studies of the physical mechanical and thermal properties of PU foam with a higher graphite content revealed a higher normal sound absorption coefficient; insignificant influence on the thermal conductivity; a higher decomposition onset temperature; more difficult ignition. PU foam sample with a ratio of 15 graphite weight fractions to 100 polyol weight fractions has the highest physical mechanical and thermal properties, and, as compared to the starting PU foam, it features an increase in normal sound absorption coefficient by an average of 3 times; a decrease in the thermal conductivity by 8 %; an increase in the decomposition onset temperature by 6.7 °С. Therefore, the modification of PU foam with expandable graphite makes it possible not only to develop hardly combustible polyurethanes but also to improve its physical mechanical and thermal properties.

Nanomaterials in PU Foam for Enhanced Sound Absorption at Low Frequency Region

2014 ◽  
Vol 938 ◽  
pp. 170-175 ◽  
Author(s):  
R. Gayathri ◽  
R. Vasanthakumari
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Foam Cell ◽  
Research Work ◽  
Low Frequency ◽  
Absorption Capacity ◽  
Polyurethane Foams ◽  
Sound Absorption Coefficient ◽  
Enhanced Absorption ◽  
Pu Foam

Lot of research is going on to develop materials suitable for absorbing sound and reducing noise. By virtue of their superior vibration damping capability and attractive characteristics such as visco elasticity, simple processing and commercial availability, polyurethane foams are extensively applied not only in automotive seats but also in various acoustical parts. However, the sound absorption coefficient of polyurethane foams is high (0.8 1.0) in high frequencies in the range 300 to 10000Hz while it is found to be low (0 to 0.5) at low frequencies (10 to 200 Hz). In this study new polyurethane based porous composites were synthesized by in situ foam rising polymerization of polyol and diisocyanate in the presence of fillers such as nanosilica (NS) and nanoclay (NC). The effect of these fillers at various concentrations up to 2% was studied for sound absorption characteristics in the frequency range 100-200Hz. Sound absorption coefficient was determined using standing wave impedance tube method. The sound absorption coefficient of filled PU foams increases from 0.5 to 0.8 with frequency increase from 100 to 200 Hz at higher content of the nanofillers employed. This research work is further extended to study the sound absorption capacity of unfilled PU foam with varying thickness and also hybrid foams with woven glass (GFC) and polyester cloth (PEC). The unfilled foam with 60mm of thickness gives sound absorption value same as that of 15mm of filled foam. Further enhanced absorption value is achieved with PU/NS-GFC hybrid. The results obtained are explained based on the porosity of composite structure and foam cell size.Key words Polyurethane foam, sound absorption coefficient, nanosilica, nanoclay, low frequency sound.

Effect of Nanocellulose on Acoustical and Thermal Insulation Properties of Silicone Rubber Composite

2019 ◽  
Vol 964 ◽  
pp. 156-160 ◽  
Author(s):  
Mohammad Farid ◽  
Agung Purniawan ◽  
Diah Susanti ◽  
Amaliya Rasyida ◽  
Henry Yulianto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Absorption Coefficient ◽  
Silicone Rubber ◽  
Sound Absorption ◽  
Wide Band ◽  
Sound Absorption Coefficient ◽  
Empty Fruit Bunch ◽  
A Value ◽  
Rubber Composite ◽  
The Matrix

Nanocellulose composites are very potential to be applied as automotive component materials.The purpose of this research is to analyze the influence of nanocellulose fraction of the silicon rubber composite material to morphology, sound absorption coefficient, density, thermal stability, and thermal conductivity. The nanocellulose of the composites were isolated from oil palm empty fruit bunch, while the matrix was silicone rubber. Tests conducted in this research included sound absorption coefficient, SEM, TGA, density, and thermal conductivity. Sound absorption coefficient had a value between 0,33 to 0.42 for a frequency of 500 Hz to 4000 Hz. This sound absorption coefficient had a wide band sound absorption tendency and was developed for sound absorption material of mufflers.

scholarly journals Acoustic, Mechanical and Thermal Properties of Green Composites Reinforced with Natural Fibers Waste

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 654 ◽  
Author(s):  
Tufail Hassan ◽  
Hafsa Jamshaid ◽  
Rajesh Mishra ◽  
Muhammad Qamar Khan ◽  
Michal Petru ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Natural Fiber ◽  
Coefficient Of Thermal Expansion ◽  
The Other ◽  
Fiber Reinforced Composites ◽  
Sound Absorption Coefficient ◽  
Mechanical And Thermal Properties ◽  
Reinforced Composites ◽  
Fiber Reinforced

The use of acoustic panels is one of the most important methods for sound insulation in buildings. Moreover, it has become increasingly important to use green/natural origin materials in this area to reduce environmental impact. This study focuses on the investigation of acoustic, mechanical and thermal properties of natural fiber waste reinforced green epoxy composites. Three different types of fiber wastes were used, e.g., cotton, coconut and sugarcane with epoxy as the resin. Different fiber volume fractions, i.e., 10%, 15% and 20% for each fiber were used with a composite thickness of 3 mm. The sound absorption coefficient, impact strength, flexural strength, thermal conductivity, diffusivity, coefficient of thermal expansion and thermogravimetric properties of all samples were investigated. It has been found that by increasing the fiber content, the sound absorption coefficient also increases. The coconut fiber-based composites show a higher sound absorption coefficient than in the other fiber-reinforced composites. The impact and flexural strength of the cotton fiber-reinforced composite samples are higher than in other samples. The coefficient of thermal expansion of the cotton fiber-based composite is also higher than the other composites. Thermogravimetric analysis revealed that all the natural fiber-reinforced composites can sustain till 300 °C with a minor weight loss. The natural fiber-based composites can be used in building interiors, automotive body parts and household furniture. Such composite development is an ecofriendly approach to the acoustic world.

scholarly journals Physical Properties of Soy-Phosphate Polyol-Based Rigid Polyurethane Foams

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongyu Fan ◽  
Ali Tekeei ◽  
Galen J. Suppes ◽  
Fu-Hung Hsieh
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Water Content ◽  
Polyurethane Foams ◽  
Solid Polymer ◽  
Mechanical And Thermal Properties ◽  
Blowing Agent ◽  
Isocyanate Index ◽  
Pu Foams

Water-blown rigid polyurethane (PU) foams were made from 0–50% soy-phosphate polyol (SPP) and 2–4% water as the blowing agent. The mechanical and thermal properties of these SPP-based PU foams (SPP PU foams) were investigated. SPP PU foams with higher water content had greater volume, lower density, and compressive strength. SPP PU foams with 3% water content and 20% SPP had the lowest thermal conductivity. The thermal conductivity of SPP PU foams decreased and then increased with increasing SPP percentage, resulting from the combined effects of thermal properties of the gas and solid polymer phases. Higher isocyanate density led to higher compressive strength. At the same isocyanate index, the compressive strength of some 20% SPP foams was close or similar to the control foams made from VORANOL 490.

scholarly journals Synthesis and Evaluation of Polyurethane Foam Composites for Enhanced Sound Absorption at Low Frequency

2019 ◽  
Vol 8 (3) ◽  
pp. 6815-6818
Keyword(s):  
Absorption Coefficient ◽  
Polyurethane Foam ◽  
Sound Absorption ◽  
Low Frequency ◽  
Weight Fraction ◽  
Crumb Rubber ◽  
Polyurethane Foams ◽  
Sound Absorption Coefficient ◽  
Filler Materials ◽  
Frequency Range

Polyurethane foams are extensively used as sound absorbing materials in various automobile parts. However, the sound absorption capability of polyurethane foam ispoorin low frequency range. The advancement of technologies to develop newerpolymer composites, provide scope to develop composite polyurethane foam with better sound absorption coefficient in low frequency range. Composite foams are made with two different filler materials as crumb rubber and coconut fiber, in varying weight fraction of up to 2.0%. Density, Sound absorption coefficient, and Noise reduction, measurements were done on all polyurethane foams. The effect offiller additionsto polyurethane foams ondensity and sound absorption coefficient at low frequency are discussed.The 1.4 % crumb rubber polyurethane foam offers the best combination of low density, improved sound absorption coefficient value and noise absorption at low frequency.

scholarly journals Vibration Damping and Acoustic Behavior of PU-Filled Non-Stochastic Aluminum Cellular Solids

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 725
Author(s):  
Vitor Hugo Carneiro ◽  
Hélder Puga ◽  
José Meireles
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Polyurethane Foams ◽  
Vibration Damping ◽  
Acoustic Properties ◽  
Sound Absorption Coefficient ◽  
Cellular Solids ◽  
Infiltration Process ◽  
Wide Range

Aluminum-based cellular solids are promising lightweight structural materials considering their high specific strength and vibration damping, being potential candidates for future railway vehicles with enhanced riding comfort and low fuel consumption. The filling of these lattices with polymer-based (i.e., polyurethane) foams may further improve the overall vibration/noise-damping without significantly increasing their density. This study explores the dynamic (i.e., frequency response) and acoustic properties of unfilled and polyurethane-filled aluminum cellular solids to characterize their behavior and explore their benefits in terms of vibration and noise-damping. It is shown that polyurethane filling can increase the vibration damping and transmission loss, especially if the infiltration process uses flexible foams. Considering sound reflection, however, it is shown that polyurethane filled samples (0.27–0.30 at 300 Hz) tend to display lower values of sound absorption coefficient relatively to unfilled samples (0.75 at 600 Hz), is this attributed to a reduction in overall porosity, tortuosity and flow resistivity. Foam-filled samples (43–44 dB at 700–1200 Hz) were shown to be more suitable to reduce sound transmission rather than reflection than unfilled samples (21 dB at 700 Hz). It was shown that the morphology of these cellular solids might be optimized depending on the desired application: (i) unfilled aluminum cellular solids are appropriate to mitigate internal noises due to their high sound absorption coefficient; and (ii) PU filled cellular solids are appropriate to prevent exterior noises and vibration damping due to their high transmission loss in a wide range of frequencies and vibration damping.

scholarly journals The Effect of Multiwalled Carbon Nanotubes on the Thermal Conductivity and Cellular Size of Polyurethane Foam

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Huynh Mai Duc ◽  
Dat Nguyen Huu ◽  
Trung Tran Huu ◽  
Lu Le Trong ◽  
Hai Luong Nhu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Fourier Transform ◽  
Thermal Properties ◽  
Multiwalled Carbon Nanotubes ◽  
Mechanical And Thermal Properties ◽  
Multiwalled Carbon ◽  
Sem Images ◽  
Pu Foam

Polyurethane (PU) foam is known as the popular material for the applications in many fields of industry and life. To improve the mechanical and thermal properties of this material, in this research, PU foam was reinforced with aniline-modified multiwalled carbon nanotubes (MWCNTs). Fourier transform infrared FTIR spectrum of modified MWCNTs showed the aniline was grafted on the surface of MWCNTs through the appearance of –NH2 stretches. The effect of MWCNTs with and without modification on the density, porosity, compressive strength, and heat conductivity of PU/MWCNT foam nanocomposites was investigated. The dispersibility of MWCNTs in the PU matrix was enhanced after modification with aniline. Compressive strength of PU nanocomposite reached the highest value after adding 3 wt.% of modified MWCNTs into PU foam. Besides, the water uptake of PU nanocomposites using 3 wt.% of MWCNTs was decreased to 13.4% as compared to that using unmodified MWCNTs. The improvement in thermal conductivity of PU/aniline-modified MWCNT nanocomposite was observed due to the change in the cellular size of PU foam in the presence of MWCNTs as shown by SEM images.

scholarly journals Experimental and Modelling Studies on Thermal Insulation and Sound Absorption Properties of Cross-Laid Nonwoven Fabrics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tao Yang ◽  
Lizhu Hu ◽  
Xiaoman Xiong ◽  
Michal Petrů ◽  
Sundaramoorthy Palanisamy ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Absorption Coefficient ◽  
Thermal Insulation ◽  
Sound Absorption ◽  
Nonwoven Fabric ◽  
Sound Absorption Coefficient ◽  
Absorption Properties ◽  
Nonwoven Fabrics ◽  
Significant Difference ◽  
Modelling Studies

Abstract Nonwoven fabrics are widely used for thermal insulation and sound absorption purpose in construction and automobile fields. It is essential to investigate their thermal conductivity and sound absorption coefficient. Five cross-laid nonwoven fabrics are measured on the Alambeta device and Brüel & Kjær impedance tube. Bogaty and Bhattacharyya models are selected to predict the thermal conductivity, and Voronina and Miki models are used to predict the sound absorption coefficient. The predicted thermal conductivity shows a significant difference compared with the measured values. It is concluded that Bogaty and Bhattacharyya models are not suitable for high porous nonwoven fabric. In addition, the results of Voronina and Miki models for sound absorption prediction are acceptable, but Voronina model shows lower mean prediction error compared with Miki model. The results indicate that Voronina model can be used to predict the sound absorption of cross-laid nonwoven fabric.

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