Abstract: The invention relates to a method for separating waste polyurethane foams, wherein for each polyurethane sample (1) of a supply stream (2) comprising polyurethane samples (1) from waste at least one respective spectrum (3) is recorded, wherein the at least one respective spectrum (3) is recorded by near-infrared spectroscopy, wherein each polyurethane sample (1) of the supply stream (2) is classified by a classification algorithm (5), which classification algorithm (5) is based on machine learning, based on the respective at least one spectrum (3) into a respective class (8a-e) of at least two classes (8a-e), wherein the supply stream (2) comprising polyurethane samples (1) is separated into at least two streams (11a-e) according to the classification into the respective class (8a-e) and wherein each class (8a-e) corresponds to a type of polyurethane. The invention also relates to a system for separating waste polyurethane foams.

Abstract: A method for alcoholising and hydrolysing polyurethane (PUR) materials made from at least one polyol compound and at least one toluene diisocyanate based compound; wherein the method comprises the following steps: contacting the polyurethane material with at least one alcoholising compound, thereby forming a reaction mixture (M0) and allowing the polyurethane material and the alcoholising compound to react in said reaction mixture (M0), thereby forming a mixture (M); allowing the mixture (M) to separate into at least an upper phase and a lower phase, wherein phase (A) and phase (B) are two immiscible phases; subjecting phase (B) to at least one hydrolysis step, thereby forming a phase (B1); wherein the at least one alcoholising compound is characterized by a melting point of lower than 200° C.; wherein the at least one alcoholising compound is characterized by a hydroxyl functionality of at least 2; and with the proviso that the at least one alcoholising compound is not glycerol.

Abstract: A method for alcoholising polyurethane (PUR) materials made from at least one polyol compound having a hydroxyl value X and at least one polyisocyanate compound; wherein the method includes contacting the polyurethane material with at least one alcoholising compound, thereby forming a reaction mixture (M0) and allowing the polyurethane material and the alcoholising compound to react in the reaction mixture (M0), thereby forming a mixture (M); allowing the mixture (M) to separate into at least two immiscible phases; wherein at least one phase is characterized by a hydroxyl value Y wherein Y?3.5*X; wherein at least one alcoholising compound is characterized by a hydroxyl functionality of at least 4 and by an equivalent weight of at most 65.0 g/mol; with the proviso that when a mixture of alcoholising compounds is used, the average hydroxyl functionality of all alcoholising compounds is at least 4 and the average equivalent weight of all alcoholising compounds is at most 65.0 g/mol.