Enhancing the Thermal Resistance of UV-Curable Resin Using (3-Thiopropyl)polysilsesquioxane

This study delineates a methodology for the preparation of new composites based on a photocurable urethane-acrylate resin, which has been modified with (3-thiopropyl)polysilsesquioxane (SSQ-SH). The organosilicon compound combines fully enclosed cage structures and incompletely condensed silanols (a mixture of random structures) obtained through the hydrolytic condensation of (3-mercaptopropyl)trimethoxysilane. This process involves a thiol-ene "click" reaction between SSQ-SH and a commercially available resin (Ebecryl 1271^®) in the presence of the photoinitiator DMPA, resulting in composites with significantly changed thermal properties. Various tests were conducted, including thermogravimetric analysis (TGA), Fourier transmittance infrared spectroscopy (FT-IR), differential scanning calorimetry (Photo-DSC), and photoreological measurement mechanical property, and water contact angle (WCA) tests. The modification of resin with SSQ-SH increased the temperature of 1% and 5% mass loss compared to the reference (for 50 wt% SSQ-SH, T_5% was 310.8 °C, an increase of 20.4 °C). A composition containing 50 wt% of SSQ-SH crosslinked faster than the reference resin, a phenomenon confirmed by photorheological tests. This research highlights the potential of new composite materials in coating applications across diverse industries. The modification of resin with SSQ-SH not only enhances thermal properties but also introduces a host of functional improvements, thereby elevating the performance of the resulting coatings.