The change of molecular weight by heating was reported in the previous paper for polyamide. This phenomenon is treated kinetically for 6-nylon in this paper. Occurence of both polymerization and depolymerization seems to be the cause of this phenomenon. Both reactions are separated, using several experimental data, and change of number of molecules by polymerization is calculated against time. It becomes clear that this polymerization reaction is the second order for number of unreacted

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... s and the activation energy of this reaction is computed as 12.7 kcal/mol form change of rate constant with temperature. Some suppositions, are made for mechanism of polymerization. * Research Laboratory , Dai-Nippon Celluloid Co. Sakai, Osaka)