Preparation of poly(thiourethane) networks by using a novel acidic organocatalyst. Evaluation of their vitrimer-like behavior

In this work, a novel acidic catalyst, isopropyl methane sulfonate, has been tested for the preparation of a series of poly(thiourethane) thermosets (PTU)s. The advantage of this compound is that in addition to being free of metals, by heating at temperatures above 100 degrees C, it releases methane sulfonic acid, which is the true catalyst allowing to maintain the formulation liquid at room temperature for a longer time than when using the more common dibutyltin dilaurate (DBTDL) catalyst. The materials obtained were characterized by thermogravimetry and thermomechanical analysis, which allow determining higher initial degradation temperatures than using tetraphenyl borate amidinium salts as basic organic catalysts. The PTUs prepared with this catalyst show good vitrimeric-like characteristics, with faster relaxation on increasing the amount of catalyst. The materials could be recycled without losing their chemical structure and mechanical performance.