Biobased Itaconate Acrylic Pressure-Sensitive Adhesives via Emulsion Polymerization: Sustainable Design for High Peel Resistance

Pressure-sensitive adhesives (PSAs) are widely used materials, yet most of their raw materials are currently derived from nonrenewable petroleum resources. The PSA industry faces challenges including the depletion of petroleum resources, high solvent emissions, and carbon-intensive manufacturing processes. To address these issues, a series of poly-(dibutyl itaconate-co-butyl acrylate-co-acrylic acid-co-glycidyl methacrylate) (PDBAG) copolymers were synthesized via high-temperature semicontinuous emulsion polymerization, using fully biobased dibutyl itaconate (DBI) as a monomer. The structures and properties of PDBAG with varying DBI and glycidyl methacrylate (GMA) contents were systematically characterized. An optimal balance between adhesion and cohesion was achieved at a GMA content of 0.5 wt %. Remarkably, increasing DBI content from 30 wt % to 50 wt % enhances the high-frequency shear loss modulus (G″) from 55.5 to 87.3 kPa (measured at T = 40 °C, ε = 1%) and correspondingly improves the 180° peel strength with SUS from 10.7 N/25 mm to 16.5 N/25 mm. This enhancement mechanism is attributed to increased energy dissipation within the PSA network during peel deformation. They surpass commercial acrylic PSAs in both peel strength and shear holding power. Biobased PSA partially replaces petroleum-based acrylics in the polymer backbone and features simpler, more eco-friendly processing while maintaining outstanding adhesion. This establishes a sustainable pathway for next-generation adhesive development.