γ-α Transition of Nylon 6 by Drawing

Abstract

By X-ray and infrared measurements on drawn and heat set specimens of iodine-treated lon 6, whose crystal form is similar to the γ-form of polyamides proposed by Kinoshita, it is found that the undrawn structure of the γ-form is destroyed and converted into the fiber structure of the usual α-form by drawing and heat setting after drawing but the fiber structure of the γ-form is stable against stretching and heat setting.
Drawing phenomenon of the undrawn iodine-treated nylon 6 is explained by using the folding model of the semicrystalline polymer. The γ-α transition by drawing and the α-γ transition by the iodine treatment of nylon 6 reject the Slichter's proposal for the structures of polyamides made from ω-amino acids which have even number of carbon atoms. To explaine these results, a new model of the γ-form of nylon 6 is suggested using Kinoshita's model of nylon 8.