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The recycling of cross-member composite (CMC) parts was studied using partial decrosslinking of the polyurethane (PUR) composite matrix by catalyzed glycolysis. The decrosslinked material, containing reactive OH and NH2 groups, was reacted with polymeric isocyanate in a molding operation to form a new composite product. In order to make the process economically feasible the smallest amounts of reactants (glycol, catalyst, isocyanate) were used in the process. The results of the laboratory study were verified in semi-pilot plant runs. The economic analysis showed that the process is feasible.

The recycling of polyurea-urethane (PUU) RIM materials, which are widely used in the automotive industry, was investigated. The process employed for the recycling PU-U RIM was based on the catalyzed chemical decrosslinking, using short chain diol as a reactant. The transesterification (decrosslinking reaction) was studied in the Haake mixer and twin screw extruder. The effect of various parameters (temperature, reactant/PU-U RIM ratio, rpm etc.), on the yield of liquid oligomers was determined. The resulting liquid oligomers were characterized using various analytical methods and used in the preparation of new products such as coatings, adhesives etc. The results showed that the catalyzed chemical decrosslinking of PU-U RIM can be a potential recycling method.