Sound absorption properties of polyurethane foams derived from crude glycerol and liquefied coffee grounds polyol

2017 ◽  
Vol 62 ◽  
pp. 13-22 ◽  
Author(s):  
Nuno Gama ◽  
Rui Silva ◽  
António P.O. Carvalho ◽  
Artur Ferreira ◽  
Ana Barros-Timmons
2021 ◽  
pp. 103872
Author(s):  
Behzad Mohammadi ◽  
Amir Ershad-Langroudi ◽  
Gholamreza Moradi ◽  
Abdolrasoul Safaiyan ◽  
Peymaneh Habibi

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shuming Chen ◽  
Yang Jiang ◽  
Jing Chen ◽  
Dengfeng Wang

Flexible polyurethane (PU) foams comprising various additive components were synthesized to improve their acoustic performances. The purpose of this study was to investigate the effects of various additive components of the PU foams on the resultant sound absorption, which was characterized by the impedance tube technique to obtain the incident sound absorption coefficient and transmission loss. The maximum enhancement in the acoustic properties of the foams was obtained by adding fluorine-dichloroethane (141b) and triethanolamine. The results showed that the acoustic absorption properties of the PU foams were improved by adding 141b and triethanolamine and depended on the amount of the water, 141b, and triethanolamine.


Polymer Korea ◽  
2020 ◽  
Vol 44 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Seung Hwan Baek ◽  
Hyeon Jun Choi ◽  
Jung Hyeun Kim

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5673
Author(s):  
Maria Kurańska ◽  
Roman Barczewski ◽  
Mateusz Barczewski ◽  
Aleksander Prociak ◽  
Krzysztof Polaczek

The main goal of this work was to evaluate the thermal insulation and sound absorption properties of open-cell rigid polyurethane foams synthesized with different contents of cooking oil-based polyol. The content of the applied bio-polyol as well as flame retardant (triethyl phosphate) in the foam formulation had a significant influence on the cellular structures of the materials. The open-cell polyurethane foams were characterized by apparent densities in the range 16–30 kg/m3. The sound absorption coefficients of the polyurethanes with various contents of bio-polyol were determined using the standing wave method (Kundt’s tube) in the frequency range of 100–6300 Hz. The effect of the content of the bio-polyol and flame retardant on the coefficient of thermal conductivity (at average temperatures of 0, 10 and 20 °C) as well as the compressive strength (at 20 and −10 °C) was analyzed. Different trends were observed in terms of the thermal insulation properties and sound absorption ability of the open-cell polyurethanes due to the addition of bio-polyol. In conclusion, it is necessary to use systems containing both petrochemical and bio-based raw materials.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 401
Author(s):  
Roberto Atiénzar-Navarro ◽  
Romina del Rey ◽  
Jesús Alba ◽  
Víctor J. Sánchez-Morcillo ◽  
Rubén Picó

The acoustic properties of recycled polyurethane foams are well known. Such foams are used as a part of acoustic solutions in different fields such as building or transport. This paper aims to seek improvements in the sound absorption of these recycled foams when they are combined with fabrics. For this aim, foams have been drilled with cylindrical perforations, and also combined with different fabrics. The effect on the sound absorption is evaluated based on the following key parameters: perforation rate (5% and 20%), aperture size (4 mm and 6 mm), and a complete perforation depth. Experimental measurements were performed by using an impedance tube for the characterization of its acoustic behavior. Sound absorption of perforated samples is also studied—numerically by finite element simulations, where the viscothermal losses were considered; and analytically by using models for the perforated foam and the fabric. Two textile fabrics were used in combination with perforated polyurethane samples. Results evidence a modification of the sound absorption at mid frequencies employing fabrics that have a membrane-type acoustic response.


2012 ◽  
Vol 37 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Bülent Ekici ◽  
Aykut Kentli ◽  
Haluk Küçük

Abstract The sound absorption property of polyurethane (PU) foams loaded with natural tea-leaf fibers and luffa cylindrica (LC) has been studied. The results show a significant improvement in the sound absorption property parallel to an increase in the amount of tea-leaf fibers (TLF). Using luffa-cylindrica as a filler material improves sound absorption properties of soft foam at all frequency ranges. Moreover, an increase in the thickness of the sample resulted in an improvement of the sound absorption property. It is pleasing to see that adding tea-leaf fibers and luffa-cylindrica to the polyurethane foam demonstrate a significant contribution to sound absorption properties of the material and it encourages using environmental friendly products as sound absorption material in further studies.


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