This study presents the synthesis of a novel biobased epoxy monomer derived from vanillin and cystamine, incorporating imine and disulfide exchangeable groups within its structure. A series of epoxy-based vitrimers with two simultaneous exchange relaxation processes have been produced using this monomer. These exchange mechanisms operate without the need for any catalyst. Four different amine curing agents have been employed to achieve vitrimers with glass transition temperatures around 100 °C and excellent thermal stability. Through dynamic-mechanical analyses, thermomechanical properties and vitrimeric characteristics have been investigated, revealing remarkably fast stress relaxation at relatively low temperatures without significant creep below the glass transition temperature. Leveraging the dual exchange mechanism, the chemical degradability of these vitrimers has been explored through two accessible methodologies, and the material's reformation after degradation has been demonstrated in both cases. Furthermore, the material has been mechanically recycled, maintaining almost the same properties. Finally, these materials have been used to fabricate and recycle carbon-fiber-reinforced composite material and reversible adhesives, showcasing their promising potential applications.

Polysulfone (PSU) membranes are widely recognized for their thermal stability, mechanical strength, and chemical resistance, making them suitable for diverse separation applications. This review highlights recent advances in PSU membrane development, focusing on fabrication techniques, structural modifications, and emerging applications. Phase inversion remains the predominant method for membrane synthesis, allowing precise control over morphology and performance. Functional enhancements through blending, chemical grafting, and incorporation of nanomaterials—such as metal–organic frameworks (MOFs), carbon nanotubes, and zwitterionic polymers—have significantly improved gas separation, and water purification., In gas separation, PSU-based mixed matrix membranes demonstrate enhanced CO₂/CH₄ selectivity, particularly when integrated with MOFs like ZIF-7 and ZIF-8. In water treatment, PSU membranes effectively remove algal toxins and heavy metals, with surface modifications improving hydrophilicity and antifouling properties. Despite these advancements, challenges remain in optimizing cross-linking strategies and understanding structure–property relationships. This review provides a comprehensive overview of PSU membrane technologies and outlines future directions for their development in sustainable and high-performance separation systems.

This study presents the synthesis of a new biobased epoxy monomer derived exclusively from biobased vanillin and epichlorohydrin. Using only sustainable processes, vanillin is first converted to vanillin amine hydrochloride, which is then condensed with vanillin to obtain a diphenol containing an imine moiety. This diphenol subsequently reacts with epichlorohydrin to produce the epoxy monomer. Unlike thermosetting networks in which the imine is formed during the curing reaction, this epoxy monomer incorporates the imine moiety, and no further processing is needed after network formation due to water release. It presents a low molecular weight (399.44 g/mol), enabling the formation of a wide range of highly cross-linked materials. The epoxy monomer can be melted at 100 °C, which facilitates its formulation with the curing agents without the need for solvents. The monomer was cured in this work with two diamines, isophorone diamine (IPDA), a commonly used curing agent, and cystamine (Cyst) as a biobased amine that contains a dynamic disulfide group, to obtain a 100% biobased material. The resulting materials were compared with DGEBA/IPDA and DGEBA/Cyst formulations in terms of thermomechanical properties to evaluate whether the new monomer could be a promising alternative to DGEBA. No less important is the fact that the presence of the imine moiety in the monomer gives vitrimeric behavior to the material. This feature enables reprocessing of the material and allows for both chemical and mechanical recycling. Such properties are particularly promising for applications such as reversible adhesives or degradable matrices in composite materials.