Influence of chemical composition on the properties and foamability with supercritical CO2 in thermoplastic polythiourethanes

Abstract

In this work, four polythiourethane films with different types of polyols and isocyanates were synthesized, characterized, and foamed. After characterization, it was also observed that the type of isocyanate has a large influence on the crystallinity and stiffness of the polymers, while the type of polyol modifies the FT-IR spectra and the decomposition curve of the material with temperature. During the foaming tests, it was observed that the polymeric foams with tolylene-2,4-diisocyanate as isocyanate were able to achieve higher values of expansion ratio, although they also suffered higher shrinkage. Moreover, these foams presented cells with higher size and heterogeneity, while the foam obtained with hexamethylene diisocyanate as isocyanate presented cells with lower size and heterogeneity but with higher cell density, proving that the selection of the isocyanate type not only has a huge influence on the properties of the polymeric material but also on the foams obtained from it.