Improved Mechanical and Sound Absorption Properties of Open Cell Silicone Rubber Foam with NaCl as the Pore-Forming Agent.

Longgui Peng,Lei Lei,Yongqiang Liu,Lifei Du

doi:10.3390/ma14010195

Longgui Peng, Lei Lei + Show 2 more

Open Access

https://doi.org/10.3390/ma14010195

Copy DOI

Journal: Materials	Publication Date: Jan 3, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: Xi'an University of Science and Technology

Abstract

Porous materials hold great potential in the field of sound absorption, but the most abundantly used materials, such as Polyurethane (PU) foam and polyvinyl chloride (PVC) foam, would inevitably bring environmental harms during fabrication. In this study, the nontoxic addition-molded room temperature vulcanized silicone rubber is chosen as the matrix, and NaCl particles are chosen as the pore forming agent to prepare open cell foams via the dissolve-separating foaming method. The effect of different amounts of NaCl (0–100 phr) on the cell structure, mechanical and sound absorption properties is investigated and analyzed. The results indicate that the cell structure could be tailored via changing the addition amount of NaCl, and open cell silicon rubber foams could be achieved with more than 20 phr NaCl addition. Open cell silicon foams show the most effective sound absorption for sound waves in middle frequency (1000–2000 Hz), which should be attributed to the improved impedance matching caused by the open cell structures. Additionally, the mechanical properties, including hardness, tensile strength and corresponding elastic properties, gradually decay to a steady value with the increasing addition amount of NaCl. Therefore, open cell silicone rubber foams are capable of sound absorption in middle frequency.

Highlights

With the rapid development of modern industry, transportation and urban construction, noise pollution has become critical issues in modern society [1]
The optimized pore structure of the silicone rubber foam could be prepared with 80 phr of NaCl in the preparation method
NaCl would result in the low porosity with connectivity closed cells, and a large addition amount of NaCl could cause increased closed cells, and a large addition of NaCl could increased of pores in the foams,amount which would result in cause different effects connectivon the mechanical and sound absorption performances

Summary

Introduction

With the rapid development of modern industry, transportation and urban construction, noise pollution has become critical issues in modern society [1]. Noise and vibration will reduce industrial production efficiencies, and be harmful to workers in industrial and noisy environments [2]. Reducing the harm caused by noise and vibration has drawn increasing attention in the fields of scientific research, industrial and so on [3,4,5]. Among them, controlling noise in the propagation path is the simplest and most effective way. Active noise reduction consists of generating sound by attaching secondary sound sources, which has the same amplitude and frequency, but the opposite phase as the main noise to achieve the purpose of sound elimination. Passive noise reduction is used to implement sound insulation and sound absorption technology. Foams are the widely designed and investigated materials to realize effective sound absorption in broadband frequency [6,7,8]

Methods

Results

Conclusion