Nano-architectured mesoporous silica decorated with ultrafine Co3O4 toward an efficient way to delaying ignition and improving fire retardancy of polystyrene

Publication date: 5 September 2017
Source:Materials & Design, Volume 129
Author(s): Zhi Li, De-Yi Wang
Aiming to impart polystyrene (PS) with delayed ignition and improved fire retardancy, mesoporous silica SBA-15 decorated with Co3O4 ultrafine nanoparticles (SBA-15@Co3O4) was nano-architectured successfully via multi-step microwave radiation approach. The design principles included: 1) SBA-15 offered the absorbing and labyrinth effect of volatiles 2) the homogeneous and ultrafine dispersion of Co3O4 on SBA-15 interior walls endowed more interacting sites to volatiles. In detail, the obtained SBA-15@Co3O4 was firstly verified using FTIR, Raman, XRD, SEM, TEM and N2 sorption measurement. Compared with neat PS and PS/SBA-15 composites, PS composites with SBA-15@Co3O4 demonstrated significantly enhanced thermal and thermo-oxidation stability. Meanwhile, PS composite with 2wt% SBA-15@Co3O4 (PS/2SBA-15@Co3O4) had a notably better fire retardancy with time to ignition (TTI) value of 116±2s, which was obviously higher than those of PS (98±1s) and PS/2SBA-15 (106±1s). Thermogravimetric analysis coupled with FTIR (TG-FTIR) and mass spectrometry (TG-MS) measurement revealed the probable mechanism of reduced heat release and delayed TTI, which was involved in the adsorption-desorption-combustion mode. Moreover, tensile test illustrated that SBA-15@Co3O4 notably improved the mechanical property of PS. Through this study, nano-architecture of functionalized hybrid offered a novel idea to delay ignition, decrease flammability while improve the mechanical properties for polymeric materials.

Graphical abstract

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