Waste Styrofoam-Based Adhesives Synthesis

The waste Styrofoam used in this study was electronic containers (WPS-1) and food containers (WPS-2). Four types of WPS-based adhesives were prepared from WPS-1 and WPS-2 and then modified with MDI and MA (Figure 1). The WPS was cleaned with AquaDes and dried at room temperature. After that, the WPS was crushed into particles. The dissolution of WPS particles was adopted from a published work with some modifications [16 (link)]. Approximately 200 g (20% w/v) of WPS particles was dissolved in 1000 mL of co-solvents consisting of 100 mL of ethyl acetate, 100 mL pf methylene chloride, 150 mL of butyl acetate, 60 mL of propanol, 90 mL of butanol, and 500 mL of toluene. The dissolution process was performed at 60 °C under continuous stirring at 100 rpm for 10 min. After all the WPS particles were dissolved, around 40 g (20% w/v) of MDI based on the WPS solids was poured into the mixture. The cross-linking reaction was performed at 60 °C under continuous stirring at 100 rpm for 30 min. The modification with MA was performed following the above procedure.