A bio-based benzoxazine surfactant from amino acids†
A novel bio-based benzoxazine (Ca-g) surfactant was synthesized via a Mannich reaction using renewable glycine and cardanol as raw materials. The structure of Ca-g was characterized by NMR, FT-IR, and elemental analysis. Styrene containing emulsions and polystyrene (PS) latex were prepared based on the Ca-g surfactant. These results showed that the Ca-g surfactant exhibited high efficiency for stabilizing styrene emulsions. An addition of only 1.7 (w/v)% stabilized the high internal phase emulsion (HIPE) with a styrene volume fraction up to 90%. More interestingly, HIPE exhibited pH-sensitivity and could be formed at pH values from 9.0 to 12.0. Furthermore, PS particles were obtained via HIPE polymerization. In addition, the in vitro cytotoxicity of Ca-g and its triglyceride emulsion was also investigated. Ca-g showed lower cytotoxicity against the HeLa cell line. A stable triglyceride-in-water emulsion stabilized by Ca-g was prepared. The bio-based Ca-g surfactant may have potential use in cosmetics and daily cleaning products.