OPTOTHERMAL PROPERTIES OF FIBERS - 4 - CORRELATION OF THE DENSITY ANDLOSS TANGENT CHANGE WITH SOME PHYSICAL PARAMETERS OF ANNEALED NYLON-6FIBERS

Nylon-6 fibres were annealed at various temperatures (90-175 degrees C ) for time intervals from 1 to 10 hours. An acoustic method has been u sed for measuring the density and the mechanical loss factor of these fibres. The variation of refractive indices and birefringences of nylo n-6 fibres was studied by two interferometric techniques: the multiple -beam interferometric method in transmission and the two-beam method b y using the Pluta polarizing interference microscope. The X-ray diffra ction technique was used to interpret the variations in optical and me chanical parameters obtained due to thermal treatments. Relations betw een the! optical data, mechanical loss factor and density with differe nt annealing conditions are given for these fibres. Illustrations are given using graphs and microinterferograms. (C) 1998 Published by Else vier Science Ltd. All rights reserved.