A. Abedi - Department of Textile Engineering Amirkabir University of Technology, Tehran, Iran
S. H. Bahrami - Department of Textile Engineering Amirkabir University of Technology, Tehran, Iran
B. Kalantary - Department of Textile Engineering Amirkabir University of Technology, Tehran, Iran

The solid-state polymerization (SSP) is a convenient method of producing high molecular weightat a relatively lower temperature. In this work, the Factors such as the particle size, the reactiontemperature and time, the nitrogen gas flow rate, initial molecular weight (M n ), extraction anddrying process on SSP of Nylon-6 were studied. The results showed that the reaction temperatureand time, and the particle size were the primary factors, and the others were secondary. The SSPmechanism of nylon-6 changes under different operating- conditions. At a given gas flow rate, theSSP reaction mechanism for a large-sized sample changes from chemical reaction control tointerior diffusion control with increasing temperature.