Study of the effect of different functionalized magnesium hydroxide prepared by mechanochemical method on the flame retardancy and mechanical properties of styrene‐ethylene‐butadiene‐styrene/polypropylene composites

Abstract

AbstractSolvent‐free synthetic methods have received more attention because of their reducing chemical waste and simplifying the process. A series of functionalized magnesium hydroxides (FMHs) were successfully modified with siloxanes containing different functional groups (Octyl: OTES, Octadecyl: OTMS, Phenyl: PTMS, Vinyl: VTEO, and 3‐Aminopropyl: APS) via a solvent‐free mechanochemical method. Ball milling conditions (such as reaction time, siloxane/MH ratio), the morphology, surface properties and particle size of the FMHs were investigated in detail and the results showed that both of the adjustment of particle size and the modification of surface of MH were successfully achieved at one time within 20 min. All FMHs were successfully converted from hydrophilic to hydrophobic except for the sample modified by the silane containing APS group. The influence of the different functional groups and particle size of FMHs on the mechanical properties and flame retardancy of styrene‐ethylene‐butadiene‐styrene (SEBS)/polypropylene (PP) composites were discussed. Compared with original MH/SEBS/PP, the FMHs/SEBS/PP composites have better tensile strength and elongation at break. When 68 wt% of FMHs were added to the SEBS/PP matrix, the composites can pass V‐0 rating of UL‐94 testing, and their limiting oxygen index values are above 32.3%. Meanwhile, the composites also exhibited strong smoke suppression.