Bio‐Based Epoxy–Ester Vitrimers Reinforced With Rice‐Straw Lignin: From Network Design to Corrosion‐Protective Coatings and Thermally Rebondable Structural Adhesives
Year: 2026
Type: article
Abstract: ABSTRACT This study examines bio‐based epoxy–ester vitrimer networks prepared from epoxidized soybean oil (ESO), divanillic acid (DVA), and rice‐straw lignin obtained by ultrasound‐assisted alkaline treatment. The COOH/epoxy ratio (0.7–1.5) and lignin loading (0–30 wt%) were varied to relate formulation, exchange dynamics, coating performance, and adhesive reusability. For ESO–DVA–1.0–L20, the coating showed a pull‐off adhesion of 9.69 ± 0.12 MPa, 182 ± 18 MEK double rubs, and a minimum mandrel diameter of 4.43 ± 0.71 mm. After 30 days in 3.5 wt% NaCl, | Z | at 0.01 Hz was approximately 1.0 × 10 9 Ω cm 2 , compared with approximately 8.2 × 10 8 Ω cm 2 for the lignin‐free analogue. Thermal treatment at 200°C for 1 h increased | Z | at 0.01 Hz from approximately 2.5 × 10 7 to 2.0 × 10 8 Ω cm 2 , corresponding to approximately 13% of the intact‐coating value (approximately 1.5 × 10 9 Ω cm 2 ). Optical microscopy, SEM, and 3D profilometry further showed reductions of 37.5% in scratch width and 44.4% in scratch depth, confirming partial rather than complete damage recovery. The same formulation reached an initial lap‐shear strength of approximately 14.7 MPa and retained approximately 89% after three rebonding cycles; its Mode‐I fracture energy was approximately 1.36–1.56 kJ m −2 .
DOI: 10.1002/app.71538
Institution: Electric Power University
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7213987461