The role of recyclates in the polyurethane industry: Environmental and economic aspects

The main objective of this article was to provide an overview of the polyurethane industry and waste treatment methods to identify the best method for polyurethane (PUR) reprocessing (recycling). To understand the need for recycling, existing knowledge will be referenced. Many literature studies discuss the role of recyclates in the polyurethane industry. According to these, the best available options to recapture value, for example, from raw materials, are polyurethane recycling and energy recovery. The research material was created via the glycolysis of polyurethane foam scrap. The experiments in this work include the glycolysis of polyurethane foam with a complex discussion of materials (polyurethane foam, glycols, catalysts, and properties of the obtained recyclate). Based on the research, analyses, and tests carried out related to glycolysis, the most appropriate conditions to recover polyols from scrap were the following reaction conditions: temperature 170–190°C; pH – basic; and atmosphere (air), which was the same for all samples. A total of 14 samples were tested. Two samples GL:12 [6:1] and GL 13 [8:1] were futher investigated. The numbers presented in brackets [6:1] mean that a ratio of 180 g of polyurethane foam and 30 g 1-3-propyleneglycol was used. The outstanding properties of glycolysate samples called GL:12 [6:1] and GL 13 [8:1] were achieved thanks to the ranges of the basic parameters (dosage time, time after dosage). The sample GL:12 [6:1] – dosage time 20 min and time after dosage 15 min and the GL 13 [8:1] sample – dosage time 22 min and time after dosage 15 min. The apparatus used for glycolysis included: reactor +heater, stirrer, feeder, reflux condenser, thermocouple, and temperature regulator. By analyzing the obtained results, it can be concluded that the most promising polyurethane waste management process is glycolysis.