The PIN FR ammonium phosphate was (APP) modified by latex, resulting in better mechanical properties of PIN FR epoxy. The modification aimed to improve hydrophobicity and thermal stability of the APP. Cationic latex was synthesised by semicontinuous emulsion polymerisation, then simply mixed in suspension with APP for 20 minutes, then washed and dried. APP and latex-treated APP were dosed in DGEBA thermoset epoxy at 8.5 – 13.5 %. Fire performance of the FR-epoxy was similar with APP or latex-APP (UL94-V0 @ 13.5% APP, versus no rating for neat epoxy), whereas mechanical properties (impact and tensile strength) were significantly improved.
“Enhance the interaction between ammonium polyphosphate and epoxy resin matrix through hydrophobic modification with cationic latex”, X. Zhang et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects 610 (2021) 125917, https://doi.org/10.1016/j.colsurfa.2020.125917