Biobased UV-Curable Solvent-Free Fluorosilicone Adhesives: Tunable Adhesion, Degradability, and Performance in Diverse Liquid Environments

With the popularization of the concept of sustainable development, biobased precursors are attracting increasing attention in the production of UV-curable adhesives. In this study, a straightforward solvent-free approach to prepare biobased adhesives was employed to synthesize methacrylic acid-modified epoxy soybean oil (AESO), which was subsequently blended with flexible hyperbranched siloxane (HPSI-HS) and hydrophobic 2,2,2-trifluoroethyl methacrylate (TFEMA) monomers. The resultant adhesive can be effectively adhered to the substrates through in situ UV curing with the help of initiators. The introduction of HPSI-HS and TFEMA not only reduced the viscosity of the adhesive, achieving a solvent-free adhesion process, but also improved the adhesion strength, flexibility, and thermal stability of the adhesives. The adhesive exhibits exceptional bonding strength to a variety of substrates, including glass, PVDF, copper, and aluminum. The adhesive is insoluble in water and can be bonded in various liquid environments including dimethyl silicone oil, artificial sweat (pH 4.7), seawater, deionized water, hydrochloric acid aqueous solution, and sodium chloride aqueous solutions. The adhesive is prone to degradation in a concentrated alkaline solution. Both the adhesion strength and degradation performance can be effectively modulated by adjusting the formulation meticulously. The multifunctional, degradable, and biobased fluorosilicone adhesive that is suitable for diverse application scenarios presents a practical approach to the advancement of green adhesives.