Preparation method of polyamide with high crystallization temperature and low gas content

The invention discloses a preparation method of polyamide with high crystallization temperature and low gas content, which comprises the following steps: S1, mixing a low-molecular-weight polyamide with water at a ratio of 1: 0.05-1: 0.85, and reacting at 50-200 DEG C for 0.1-24 hours in a closed state; S2, at a negative pressure state, raising the temperature at the speed of 10 DEG C/60 to 10 DEGC/360 minutes, and raising the temperature of an obtained reaction system to 160-300 DEG C; S3, after heating operation in the step S2, cooling the reaction system to 100 DEG C or below at the speedof 10 DEG C/60 to 10 DEG C/360 min in a negative pressure state, so as to obtain the polyamide with high crystallization temperature and low gas content. The method is mild in reaction condition, theprepared polyamide is high in result temperature, the content of organic matters in discharged waste liquid is low, and the method is economical and environmentally friendly and has good industrial application prospects. 本发明公开了