Preparation and property characterizations of functional rubber aerogels from recycled waste tire rubber powder

Given the annual generation of approximately 1.5 billion tons of waste tires, there is an urgent need for sustainable and environmentally friendly recycling technologies to facilitate the circular economy. Here, this work developed a novel methodology for the synthesis of rubber aerogel (RA) using waste tire rubber powder. The fabrication process employs cost-effective freeze-drying technology to combine rubber powder with polyvinyl alcohol (PVA), glutaraldehyde (GA), and xanthan gum (XG) to successfully fabricate RA with a 3D network porous structure. The density and porosity of RA obtained under the relatively optimized experimental parameters were 0.0697 g/cm3 and 94.36 %, respectively. Furthermore, the size of RAs was adjusted by molds to meet specific application requirements. RAs exhibit good compression characteristics, with a Young's modulus of 162.9 kPa. They also demonstrated excellent thermal insulation characteristics, and remained stable at temperatures below 200 ℃. The RAs modified through surface modification technique, had a water contact angle of 146° and demonstrated hydrophobic stability. This study presented a sustainable and environmentally-friendly technological approach for recycling waste tires, and established the groundwork for the development of RAs as a heat preservation material, oil adsorbent and other potential applications.