Thermoanalytical study of polyurethane, subjected to ionizing radiation, as raw material for catheters for clinical practice

Abstract

The present work aimed to study the thermal behavior of commercial polyurethane catheters before and after irradiation, in order to characterize the polymeric material of these catheters. Fourier transform infrared spectroscopy (FTIR) enabled the identification of functional groups in the structure of macromolecules, such as poly(esterurethane) and poly(etherurethane) in catheters of various origins, and it was confirmed that is a poly (etherurethane) sample. DSC and TG were employed to observe the changes in the properties of the material before and after degradation. DSC curve at the constant heating and cooling rate allowed the characterization of thermal properties, such as Tm and Tg of copolymers, as well as highlighting the main thermal events. TG provided Tonset and Tpeak DTG, where it was possible to evaluate the thermal degradation and the mass loss of the polymer, resulting from a physical transformation such as evaporation or chemical as degradation, in a continuous process as a function of temperature. The comparative assessment conducted between the catheters before and after irradiation by FTIR, Raman and DSC enabled the use of radiation as agent of sterilization.