Initially, techniques including room temperature (20°C) ball milling, grinding, or tear were tested on the different polymers due to the ease of availability. However, these were unsuitable for producing powders of micro-particles for almost all of the samples. Instead of fracturing, many plastic samples would deform plastically. 0.5 g to 2 g of the plastics were cut into approximately 5-millimeter pieces, where necessary. These samples were then placed into standard grinding vials and loaded into the cylindrical chamber of a cryogenic freezer mill (6775 Freezer mill from Spex SamplePrep). Liquid nitrogen was introduced into the chamber, pre-cooling the plastics to -150°C for 20 minutes. Subsequently, the materials underwent three grinding cycles, each lasting 2 minutes, with 2 minutes of inter-cooling time between cycles. The grinding speed of the mill was maintained at 12 cycles per second.