Characterization of Poly(Ethylene Terephthalate) by Torque Rheometry

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 24; no. 2; p. e20200238
• Main Authors: Andrade, Daniella Stepheny Carvalho, Canedo, Eduardo Luís, Carvalho, Laura Hecker de, Barbosa, Renata, Alves, Tatianny Soares
• Format: Journal Article
• Language: English
• Published: Sao Carlos Universidade Federal do Sao Carlos, Departamento de Engenharia de Materiais 2021; ABM, ABC, ABPol; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Degradation; ENGINEERING, CHEMICAL; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; Poly(ethylene terephthalate); Polyethylene terephthalate; Polymer matrix composites; Polymers; Process parameters; Pseudoplasticity; Rheological properties; Rheology; Rheometry; Rotor speed; Temperature; Torque; Viscosity; Viscosity; Degradation; Rheology; Poly(ethylene terephthalate)
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2020-0238

Polymer processing parameters may considerably affect final product characteristic as, if properly chosen, these parameters may lead to products with optimal properties. The aim of this work is to evaluate the rheological characteristics of poly(ethylene terephthalate) (PET) by torque rheometry, as well as to estimate its incipient degradation rate during processing in an internal laboratory mixer. In order to estimate the temperature coefficient of the viscosity (β), and the pseudoplasticity index (n) of PET, two sets of experiments need to be performed. In the first one, the polymer is processed at three different temperatures at a single rotor speed for 10 min, getting temperature coefficient of the viscosity equal to β = 0.053 °C-1. In the second set of experiments, the resin (PET) is processed at a single temperature at six different rotor speeds for the same time interval and the pseudoplasticity index was determined, n = 0.78. From the results obtained, it is possible to indicate the internal mixer as an equipment not only for mixing polymers or composites, but as a tool for determining important rheological variables for predicting degradative processes.