Estimation of the tensile modulus of polyethylene based on single calorimetric curves

Abstract

This study focuses on the prediction of the tensile modulus of polyethylene based on a previously developed empirical model. Just as in earlier works, the stiffness is estimated from the data evaluated from single calorimetric curves. During the work, three types of polyethylene (LDPE, MDPE and HDPE) were used. Calorimetry was employed to measure the degree of crystallinity and melting characteristics of the polymers investigated in this study, while the mechanical properties were evaluated through tensile tests conducted on standard-shaped specimens. The specimens intended for the tests were produced by injection molding and later annealed at various temperatures. The stiffness of the perfectly crystalline polymer was determined based on the propagation velocity of longitudinal sound waves in the material. The predicted and experimentally determined modulus values demonstrated a reasonably good agreement. These results verify the effectiveness of our prediction method in accurately estimating the tensile modulus of PE.