Bio‐Based Castor Oil Derivatives Synthesized From 2‐Hydroxypropyl Ricinoleate and Ricinoleic Ethanolamide for Wood Coating Applications

Abstract This work presents the synthesis of two molecules, methacrylated 2‐hydroxypropyl ricinoleate (2‐HPR MMA) and methacrylated ricinoleic ethanolamide (ROEA MMA), appropriate for wood coating applications. The synthesized compounds are structurally verified by ¹ H NMR, ESI‐MS, FT‐IR, and XRD. The rheological measurements, DSC, TGA, and the mechanical tensile and flexural tests provided a complex investigation of properties. Eventually, the coating applicability is evaluated by the standardized ISO 2409 cross‐hatch test and the Wolff‐Wilborn test. Both proposed curable molecules, 2‐HPR MMA and ROEA MMA, exhibit comparable rheological profiles and thermal properties to the reference, Castor Oil MMA. From the mechanical properties and coating applicability standpoint, 2‐HPR MMA and ROEA MMA perform considerably better than the reference. ROEA MMA reached the best‐performing results: the tensile modulus reached 155 ± 6 MPa Methacrylated Castor Oil (Castor Oil MMA's value reached 9 ± 1 MPa), the flexural modulus attained 166 ± 2 MPa (Castor Oil MMA's value reached 8 ± 3 MPa), the tensile strength recorded 9.4 ± 0.5 MPa (Castor Oil MMA's value reached 0.4 ± 0.1 MPa), and the flexural strength reached 6.1 ± 0.2 MPa (Castor Oil MMA's value reached 0.8 ± 0.0 MPa).