Advanced Fabrication and MULTI-Properties of Rubber Aerogels from CAR Tire Waste

End-of-life tires should be considered as one of the fastest-growing waste streams in the world. The annual production of waste tires is estimated to amount to 1.5 billion whole-tires worldwide. This study, for the first time, develops a simple but cost-effective method to fabricate a novel material-rubber aerogel using recycled tire polymer fibers (RTPF) shredded from car tire waste, polyvinyl alcohol (PVA) and glutaraldehyde (GA) by freeze-drying method. They are extremely light, highly absorbent, very durable, and they are also very efficient at trapping heat and sound. Rubber aerogel has ultra-low density (0.020–0.091 g/cm³), high porosity (92.2–98.3%) and excellent heat insulation properties (0.035 – 0.049 W/m.K). It has a high noise reduction coefficient (0.56) and performs 1.4 time % better than commercial sound foam absorber. The oil absorption capacity of the rubber aerogel is measured up to 25 g/g, approximately twice the absorption capacity of conventional absorbent like polypropylene mat. Rubber aerogel also shows very good durability as it springs back to its original shape after compression tests. By upcycling waste rubber into products of a higher commercial value, this new technology promotes the wider use of scrap tyres and offers an eco-friendly way to recycle used rubber.