Pyrolysis of polyamide 6 under catalytic conditions and its application toreutilization of carpets

epsilon -caprolactam is a monomer of high value. Therefore, the chemical re utilization of polyamide 6 containing carpets for epsilon -caprolactam reco very offers some economic benefit and is performed on a technical scale wit h the help of the Zimmer-process. By this process polyamide 6 is depolymeri zed with steam and phosphoric acid. An alternative to this process is the t hermal depolymerization - catalyzed or non-catalyzed. To investigate this a lternative in more detail, the formal kinetic parameters of (i) the thermal depolymerization of polyamide 6, (ii) the thermal depolymerization in pres ence of sodium/potassium hydoxide, and (iii) the thermal depolymerization i n presence of phosphoric acid are determined in this work. Based on the kin etics of the catalyzed or non-catalyzed depolymerization a stepwise pyrolys is procedure is designed by which the formation of E-caprolactam from polya mide 6 can be separated from the formation of other pyrolysis products. (C) 2001 Elsevier Science B.V. All rights reserved.