Studies on the Relationship Between Structure and Viscoelastic Properties of PET Fibres
Zang Yi;Liu Guiqing
In this paper, the relationship between structural state andmechanical properties of PET fibres is deduced on the basis ofexperimental results of dynamic mechanical properties. For PET fibreswith different super-molecular structure, the temperature dependance oftheir dynamic mechanical properties is obviously different. Furthermore,it is recognized that, in the temperature scanning process, there aretwo effects: on one hand, the modulus of the fibres decreases with theraising of temperature, but on other hand, the modulus increases dueto crystallization of the fibres. The summation of these two effectscauses the fibres with different thermohistory displaying characteristiccurves. So it is possible to determine the stability of fibre structurefrom the testing results of dynamic mechanical properties. Based onthe change of sample size during testing process of dynamic viscoelasticproperties, it is possible to determine the distribution of thermaldeformation under constant tension in wide range of temperatures. Thisdistribution characterizes thermal shrinkage behavior of fibres in thetextile processing.