Investigations on the deblocking reactions of blocked polyisocyanates synthesized from solid waste styrofoam by a non-isocyanate approach and its application in the fabrication of epoxy-polyurethane films

Few studies have reported recycling waste Styrofoam by chemical modification and used in lab scale applications; however, given the enormous amount of waste polystyrene (WPS) that is transferred to land fill, where it accumulates indefinitely and is hazardous to humans due to its complexity and during the degradation process, a scientific method that helps to recycle on a large scale is required. WPS was chemically converted into an amino compound via nitration in order to get a precursor for a novel blocked polyisocyanate (BI) via a non-isocyanate approach, which can be used as a petroleum feedstock substitute. The degree of BI substitution was calculated and found to be about 13% and 22%. Different analytical techniques were used to determine the deblocking temperature. Epoxy-polyurethane composite films with differing proportions of BI were made using waste polystyrene based blocked polyisocyanate (BI-WPS). Thermal, mechanical, & hydrophobic studies show that these new BI can be used in coating, adhesive, sealant, and elastomer application areas which require large quantity of BI-WPS.