Abstract: The dispersive and stable aqueous polyurethane emulsion was prepared by IPDI, DMPA, poly (propylene glycol) as raw material and EA as chain extender without solvent. The production was characterized by FTIR and granulometer. The influence of the ratio between soft and hard chain segments and the content of PPG adding into the soft chain segment on mechanical and waterproof property of film were investigated. The influence of content of hydrophilic group on waterproof property was also investigated. The results show that flexibility and waterproof characteristic of film are improved with increasing content of the soft chain, and mechanical strength and waterproof property of the film are improved with increasing content of PE added to soft chain.

Key words: DMPA, nonsolvent method, aqueous polyurethane