2023 Volume 23 Issue 2 Pages 126-131
To determine the optimal molding conditions for thermal imprinting, it is necessary to understand the thermo-viscoelastic properties of polymer obtained by compression tests. This is because contact resistance acts at polymer/mold interface in compression tests, and this contact resistance may affect the thermo-viscoelastic properties. Furthermore, this contact resistance may depend on the specimen thickness. In this study, static compressive creep tests were performed on polycarbonate specimens (3 mm in diameter) with different thicknesses ranging from 0.5 to 5 mm to investigate the effect of contact resistance on thermo-viscoelastic properties. The results showed that specimen thickness had little effect on the shift factor. In contrast, the creep function was affected, and the stress relaxation time was slower with thinner specimen thickness. By clarifying the relationship between the shift amount on the logarithmic time axis of the creep function and the thickness of the specimen, it was possible to predict the creep function of a thin plate specimen from that of a bulk specimen.
