A sustainable acoustic customization of open porous materials using recycled plastics

Abstract

Foams are commonly used as sound absorbers and thermal insulators for many industrial and construction applications. The insulating materials market is currently dominated by inorganic fibres like glass and mineral wool, as well as plastic foams. However, worldwide plastics consumption produces huge amounts of waste, generating concerns about soil, air and especially seawater pollution. Hence, new methods for recycling marine microplastic litter according to cleaner production criteria are being sought. This paper presents a novel, sustainable and eco-friendly foamy material made of microplastic waste, namely polyethylene terephthalate (PET) and polystyrene (PS), incorporated into a bio-based matrix. Samples with different compositions were prepared and then characterized for sound absorption properties. Evidence is presented of very good acoustic performances and of how the acoustic characteristics of the end product can be customized using different microplastic content and type. This allows envisioning many industrial and civil applications for this novel open-cell material.

Innovative Thermal and Acoustic Insulation Foams from Recycled Fiberglass Waste

“…As discussed in other works, the porosity of our foam samples is predominantly open. [15,26] With this configuration, the thermal insulation properties are slightly reduced with respect to a closed-pore material but the sound insulation capabilities are improved, [27] and this is well reflected by the good soundproofing performances recorded. Varying the alginate concentration between 2.5 and 3.5 wt.%/vol.% does not seem to affect the sound absorption properties, while the addition of plasticizing molecules (glycerol and sorbitol) seems to shift the absorption maximum to lower frequencies and improve the overall NRC values, most likely due to the softening of the structure.…”

Reinforcement of the thermal stability and mechanical properties of low-density polyethylene/high-density polyethylene foam using a modified calcium sulfate whisker

“…[1][2][3][4] Hence, PE foams have a wide range of applications in various fields including construction materials, thermal and/or sound insulators, packaging, automotive components, healthcare and sports equipment, etc. [5][6][7] Cross-linking is one of the important parameters that can affect the foaming behavior of PE resins. 8 The formation of a cross-linking network is beneficial to enhance melt strength, mechanical properties, and dimensional stability of PE resins.…”