Synthesis and function studies on formaldehyde adsorption of PEI-PU copolymers

The molecular structure of branched-chain polyethyleneimine (PEI) was determined by 13C NMR, which guided the reaction of the primary amine groups in the PEI molecule with IPA-protected MDI-PTMG monoisocyanate polyurethane prepolymer to prepare PEI copolymer-modified polyurethanes (PEI-PUs). The successful synthesis of the PEI-PUs was verified by 1H NMR tests. The results of the formaldehyde adsorption test showed that the active secondary amine groups in the PEI-PU film showed high adsorption ability of formaldehyde gas at room temperature, with an absorption up to 0.804 mmol HCOH/mmol -NH-, which has the potential to be a low-VOC functional polyurethane material.