Stress – strain behavior of Poly(ethylene terephthalate) (PET) during large Plastic Deformation by Plane Strain Compression. Part II: The Stress – Strain – Temperature (SST) Superposition Principle

 

Elton Luís Gasparotto Denardin,  Dimitrios Samios*

 

1. Laboratório de Instrumentação e Dinâmica Molecular,
Instituto de Química/UFRGS.;
 Av. Bento Gonçalves, 9500, Cx. Postal: 15003,
Porto Alegre – RS, CEP: 91501-970, Brazil

 

ABSTRACT

 

      The temperature effect on the stress – strain behavior obtained during plane strain compression of poly(ethylene terephthalate) (PET) was studied using a specific device which permitted well controlled temperature, strain rate and the application of pressures up to 650 MPa. Annealed and non-annealed PET samples obtained by injection molding were studied. It is demonstrated that the Stress – Strain – Temperature (SST) superposition principle can be well applied to describe the behavior of the studied system. The thermo-mechanical history of the annealed and non-annealed materials is clearly depicted into the Stress-Strain-Temperature superposition master curves indicating transitions related to the Tg and the crystallization of the samples. 

 

Keywords: Stress – strain – temperature superposition, plane strain compression, PET



*Corresponding author: Tel.:+55.51.33166290; fax:+55.51.33167304; e-mail: dsamios@iq.ufrgs.br , edenardin@iq.ufrgs.br