Fluorine Free Bio-Based Polybenzoxazine Coated Substrates for Oil-Water Separation and Anti-Icing Applications

Eugenol (E) based mono-functional benzoxazine(E-x) monomers were prepared using different long-chain monoamines(x = ba, ha, dda, oda) and fluorine substituted aromatic monoamine (x = fa). The molecular structure of the monomers developed was characterized by FTIR and NMR spectral analysis. Further, the prepared monomers were coated over the cotton fabric and studied for their surface behavior. The poly(E-dda) coated cotton fabric exhibits the higher value of water contact angle (WCA = 151°) than that of other samples coated with polybenzoxazines(E-ba, E-ha,E-oda, and E-fa). Furthermore, poly(E-dda) coated cotton fabrics also displayed the lower value of surface energy of 15.6 mN/m with a lower sliding angle value(11°) than those of other coated cotton fabric samples. The formation of rough surfaces on the fabric was ascertained from microstructure analysis and thereby contributes to superhydrophobicity along with pH robustness. Subsequently, the oil-water separation efficiency and flux of the poly(E-dda) coated cotton fabric was found to be 98% and 5800 L/m2h respectively. It was also observed that the specimen of a glass substrate coated with poly(E-dda) exhibited the delayed ice formation. Data obtained from different studies, it is suggested that the eugenol-dodecylamine(E-dda) based benzoxazine can be effectively employed as an alternate to fluorine-based polymers.