tetramethylimidazolidinediylpropylamine (tmbpa) in sustainable polyurethane systems for marine applications abstract: polyurethane (pu) materials are widely used in various marine applications due to their excellent properties, including durability, flexibility, and resistance to degradation. however, traditional pu synthesis relies heavily on petroleum-derived polyols and isocyanates, raising environmental concerns. the development of sustainable pu systems utilizing bio-based polyols...