Viscoelastic and Thermal Properties of Undrawn Monofilament Polypropylene Yarn

Abstract

The paper presents the viscoelastic (stress-strain curves, modulus of elasticity and yield stress) and thermal (differential scanning calorimetry thermograms) properties of the as spun polypropylene monofilament yarns produced at different spinning temperatures and modes of quenching. The basic objective of the research is to present the influence of the spinning temperature and mode of cooling on the viscoelastic, thermal and structural properties of the as spun polypropylene monofilament yarns. The PP monofilament yarns were produced at five different spinning temperatures and three different quenching modes. The research showed that higher stresses at every point of deformation are observed at lowest spinning temperatures. The as spun monfilament yarns have bilateral structure of which the more intensively quenched part has higher orientation and less perfect - supermolecular structure.