Hydrothermal treatment of polyamide 6 with presence of lanthanum chloride

Hydrothermal processing of polyamide 6 (PA6) with the presence of lanthanum chloride (LaCl3) was studied in the temperature region from 160 °C to 250 °C. PA6 will be dissolved in the superheated water when temperature is above 160 °C. And as PA6 is dissolved, hydrolysis will happen, which makes PA6 chains degrade. By adding LaCl3 in the hydrothermal environment, the PA6 hydrolysis will intensify, especially when the hydrothermal temperature is higher than 200 °C. When the hydrothermal system cools down, the hydrolyzed PA6 segments will crystallize from the solution or remain dissolved in the solution depending on molecular weight. In addition, the hydrolyzed compound of LaCl3 would affect the crystallization of PA6 segments with proper size, and γ phase would be presented.