Abstract: In order to realize the best performance of PMI foam under rational storage condition, this paper investigated the moisture absorption performance, the mechanical and thermal creep properties after moisture absorption of PMI foam. It is found that, PMI foam has the fastest absorption rate in the first 15 days after being exposed to humidity air. Moisture absorption saturates after around 120 days. The compression strength after moisture absorption is consistent with the dried one in the room temperature. However, the high temperature compressive creep performance declines significantly. The impact of compressive creep performance after drying was also discussed.

Key words: polymethacrylimide, shelf life, moisture absorption, compression property, tensile property, compressive creep