Polymer composite material fabricated from recycled polyethylene terephthalate (PET) with polyurethane binder for potential noise control applications

This paper shows a composite material fabricated from plastic waste of polyethylene terephthalate (PET) and polyurethane as binder, in a ratio of 85/15, respectively. With 85wt% of PET waste, these materials are quite significant as pollution reducer. The waste was obtained from plastic recycle bottles cut in a mechanical grinder, resulting in concave scales, later impregnated with a formulation based on polyester resin as binder, aiming to have acoustic absorption properties. This process does not involve heat treatment or curing process, and samples were manufactured with the following thickness: 10, 20 and 30 mm. Comparing the PET-polyurethane resin composite with a sampler of commercial acoustic blocks the PET composite is between 50 and 175 times stronger than the commercial solution. The acoustic characterization was conducted with an impedance tube fabricated following ASTM 1050-19 guidelines. Compression tests were conducted and the microstructure of samples was evaluated with scanning electron microscopy. A good acoustic absorption performance of the prepared material could be observed for the frequency bands of 125 Hz, 1 kHz and 4 kHz, whit absorption coefficient at normal incidence of 0.8, 0.3, and 0.2, respectively, and, therefore, able to use as a material for acoustic insulation in double partitions and sandwich-composite panels.