Elton Luis Gasparotto Denardin

Time–temperature dependence of the thermo-oxidative aging of polychloroprene rubber: The time–temperature-transformation (TTT) superposition method and the lifetime prediction

Abstract The time–temperature dependence of the thermo-oxidative aging of polychloroprene rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.

Thermal Degradation of Aged Chloroprene Rubber Studied by Thermogravimetric Analysis.

Abstract The thermal degradation of original and aged chloroprene rubber was studied using thermogravimetric analysis. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (...

Stress-Strain Behavior of Polyethylene Terephthalate) (PET) During Large Plastic Deformation by Plane Strain Compression. Part II: The Stress-Strain Temperature (SST) Superposition Principle

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.