Vulcanization on Polymer Film Surfaces With Elemental Sulfur

Elemental sulfur has been widely utilized as a sustainable feedstock for the synthesis of sulfur-modified and sulfur-rich polymers. This study aims to extend the sulfur chemistry to surfaces vulcanization of polymer films. The process involves the infiltration of molten sulfur into the polymer film from surface, followed by in situ vulcanization. The surface vulcanization yields a vulcanized polymer layer on the top portion of the polymer film, resulting in an asymmetric structure. To demonstrate this synthetic route, a mainchain polybenzoxazine (PBz) film is employed. The resulting surface vulcanized and crosslinked PBz films are characterized using a scanning electron microscopy equipped with an energy-dispersive X-ray, an X-ray photoelectron spectroscopy, and a Fourier transform infrared spectroscopy. The surface vulcanization strategy establishes a platform for the development of preparation of a new class of sulfur-containing materials.