Polystyrene Recycling via Camphene to Produce Controlled Porous Thermoplastic
Polystyrene is a thermoplastic polymer that, in theory, can be recycled indefinitely. However, due to its cost-effectiveness and low-density properties, the recycling process is not economically viable and resulted in many environmental issues. Camphene, a nontoxic and bio-derived terpene, has the potential to help mitigate polystyrene recycling. Its low melting point (50 ॰C) allows polystyrene to mix in the liquid phase under mild temperatures and crystallize at room temperature. Moreover, camphene’s high vapor pressure allows camphene to sublime from the polystyrene-camphene mixture, leaving a concentration-dependent interconnected microporous structure. This porous polymer has many potentials, ranging from lightweight structure material to filtration to binding for battery electrodes. Additionally, the sublimed camphene can be recovered significantly (>80%) and reused for successive batches of mixtures. After testing the mixtures’ rheological properties, another route of material processing of direct-ink writing (DIW) 3D printing was also able to be tested at mild temperatures of below 50 ॰C. In the end, a techno-economic analysis was performed, resulting in the limits of production scales in modular systems.