Molecular dynamics calculations were made of the distance from the hydrogen atom of the imino group to the oxygen atom of the sulfone group of polyiminosulfone (PIS). The results showed that theoreti cally there was hydrogen bond formation between the imino group and the sulfone group of PIS. The exist ence of the hydrogen bonding between the polymer chains of PIS was confirmed by infrared spectrum analysis. Due to the existence of the hydrogen bonding, PIS showed strong molecular interaction with a large cohesive energy density (CED), and a high glass transition temperature (282°C).
