The thermal behavior of epoxy–siloxane amine composites

To obtain composite materials using epoxy-functional siloxanes, direct amine addition to epoxy groups is thought to be a particularly useful approach for crosslinking epoxy, and they are used as the most popular curing agents.

In this study, we focused on an epoxy–siloxane amine composite obtained by the reaction between 1,3-Bis(3-glycidyloxypropyl)tetramethyldisiloxane (DS-PMO) and an aromatic amino compound, p-Phenylenediamine (PPDA). Two stages were involved in the preparation of the epoxy–siloxane amine composites. In the first stage, the hydrosilylation reaction between allyl glycidyl ether (AGE) and 1,1,3,3-tetramethyldisiloxane (TM-DS) was performed in the presence of a Karsted catalyst, resulting in the glycidoxypropyldisiloxane (GP-DS) intermediary compound. In the second stage, the GP-DS derivative was modified with PPDA to obtain the epoxy–siloxane amine composites (PPD-DS).

The polymers' structures were confirmed by FTIR, ¹H-NMR, and MS spectroscopy. The morphology and surface chemical compositions were highlighted using scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX). The samples were subjected to thermal investigations using thermogravimetric analysis (TGA) as well as advanced thermogravimetric analysis, namely TGA/FT-IR/MS. In addition, the optical properties and static contact angle of precursors and the synthesized sample were investigated. The results showed that modifying epoxy–siloxane with p-Phenylenediamine allows for the production of hybrid materials with very good thermal stability, and it can also be recommended to use the PPD-DS composite material for UV-based applications.