Drought Tolerant Plants’ Fiber and Recycled PET Co-Fibrous Composite as Acoustic Absorbers and Thermal Insulators

Abstract

In this paper, the series of co-fibrous composite materials combining natural fiber derived from drought-tolerant plants (pineapple, hemp, sisal, and agave) and recycled-polyethylene terephthalate (r-PET) were successfully prepared using a mixing-hot-pressing method. The area density and thickness of prepared co-fibrous materials were controlled and porosity was calculated. The co-fibrous materials with higher porosity showed better performance in sound absorption and thermal insulation. Furthermore, all prepared co-fibrous materials have a noise reduction coefficient (NRC) higher than the high-efficiency sound absorber standard at 0.56, making them comparable to commercially available products. Regarding sound absorption performance at a high frequency of 2–5 kHz, the prepared co-fibrous materials exhibited exceptional sound absorbing performance with a sound absorption coefficient (SAC, αH) ranging from 0.94 to 0.97. In terms of thermal insulation performance, both pineapple and hemp co-fibrous materials demonstrated a low thermal conductivity value of 0.029 W/mK, placing them in the range of commercial polyurethane (PU) insulating materials. In conclusion, the pineapple and hemp co-fibrous composite demonstrate potential as alternative eco-friendly commercial sound absorbers and insulators that can subsidizing petroleum-based products.