Abstract
The effects of prehistory has been studied by the measurements of rheological properties of polypropylene melts and of physical properties of as spun filaments obtained from two samples having different prehistory. One (sample A) is prepared by quenching the melt screw extrudated. The other (sample B) is prepared by the solution crystallizing from the dilute solution in xylene. These samples are well characterized by means of x-ray diffraction and dilatometry. The results of the melt viscosity, die swell and spinnability of the melt show differences according to the differences in the prehistory: the melt properties are affected by the difference in entanglement between sample A and sample B. It is found from the measurements of thermal shrinkage and tensile testing that as spun filament A having certain prehistory has a larger fraction of tie chain and that as spun filament B free from the prehistory is rich in the fold type crystal fraction.
