CATALYTIC HYDROTHERMAL DEPOLYMERIZATION AND KINETICS OF NYLON 6

摘要

Depolymerization of nylon6 to ε-caprolactam with environmental-friendly heteropolyacid catalyst at temperatures between 553K and 603 K, under different pressures of 6.4-12.8 MPa in water medium. The products of depolymerization were analysed qualitatively and quantitatively by means of FT-IR, LC/MS and HPLC. The results indicated that the main depolymerized product was ε-caprolactam. Remnants solid product was undepolymerized nylon6 and the liquid products contained a little 6-aminocaproic acid and oligomer. The highest yield of ε-caprolactam was 77.96% at 573K under 85min.Compared with no catalyst, the depolymerization rate and yield of ε-caprolactam was high under catalytic condition. Temperature and time also had important effect on depolymerization reaction. Catalytic depolymerization kinetic at different reaction conditions was studied,where the reaction activation energy was evaluated to be 77.38kJ/mol.