Preparation and characterization of flame retardant form-stable phase change materials composed by EPDM, paraffin and nano magnesium hydroxide

Paraffin, one of the important thermal energy storage materials, possesses various desirable characteristics (e.g. high heat of fusion, variable phase change temperature, self-nucleating, no phase segregation and low cost), but has low thermal stability and is flammable. In the current study, form-stable phase change materials (PCMs) based on EPDM (supported material), paraffin (dispersed phase change material), nano structured magnesium hydroxide (nano-MH) and red phosphorus (RP) with various compositions were prepared. The self-synthesized nano-MH has a kind of lamellar structure with good dispersal as characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The constructional morphology, thermal stability, latent heat and flame retardant properties of as-prepared form-stable PCM blends were evaluated by using a scanning electron microscope (SEM), thermogravimetric analysis (TGA), a differential scanning calorimeter (DSC) and limited oxygen index (LOI) tester, respectively. The SEM and DSC results show that addition of nano-MH and RP has no apparent negative effect on EPDM/paraffin three dimensional netted structures and latent heat. The TGA curves indicate that inducing the nano-MH into the form-stable PCM blends leads to the reinforcement of thermal stability, increasing the amount of char residuals at 700 °C thereby improving the flame retarding performance.