Scale‐up fabrication and advanced properties of recycled polyethylene terephthalate aerogels from plastic waste

Abstract

Traditional fabrication methods of aerogels are time consuming, toxic, and difficult to implement, making the production of aerogels expensive and severely limits widespread adoption. Nonwoven technology is introduced to prepare fibers that can be used to create polymer‐based aerogel. With its introduction, it allows the continuous flow of fine fibers and eliminates the bottlenecking fiber preparation phase of the fabrication process. Using recycled polyethylene terephthalate (rPET) fibers and polyvinyl alcohol, two types of rPET aerogels are successfully fabricated, namely the lab‐scale and the large‐scale aerogels, to investigate the effectiveness of the nonwoven process line for the fiber preparation processing step. Fibers prepared manually (lab‐scale aerogels) and with the aid of a fiber preparation production line (large‐scale aerogels) are characterized and compared. Both lab‐scale and large‐scale aerogels exhibited the required specifications of low densities (12.6–45.9 and 13.2–43.7 mg/cm3, respectively) and high porosity (99.1%–96.7% and 99.0%–96.8%, respectively). Their thermal conductivity (23.4–34.0 and 23.2–31.9 mW/m⋅K, respectively) and compressive modulus (4.74–21.91 and 4.53–22.29 kPa, respectively) were also relatively similar. The advantage of scaled preparation of fibers for aerogel manufacturing includes higher throughputs (the line can produce up to 60 kg/h), improved consistency for defibrillation, homogenous fiber blending, and accurate replication of laboratory‐made aerogel properties. This demonstrates the viability of using nonwoven technology to scale for continuous production to bring down the production cost.Highlights Scale up production of aerogels using nonwoven technology Improving preparation process of aerogels through homogenous fiber blending Preparation rate of up to 60 kg/h Developed high porosity aerogels up to 99% Good thermal insulation of 23.2–31.9 mW/m⋅K