Abstract
Lauric acid (LA)/polyethylene terephthalate (PET) ultrafine composite fibres as form-stable phase change materials (PCM) were prepared successfully via electrospinning. The morphology, thermal energy storage properties, thermal stability and flammability properties of electrospun LA/PET composite fibres were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and microscale combustion calorimetry (MCC), respectively. It was found by SEM investigation that the average fibre diameter generally increased with increasing content of LA in the LA/PET composite fibres. The morphology of electrospun composite fibres changed from a cylindrical shape with a smooth surface (without LA) to a rough and non-uniform structure (with LA). The DSC measurements indicated that there was little change of the phase transition temperatures of the composite fibres, but there was a decrease of the heat enthalpies compared with the pure lauric acid. The TGA results showed that both the onset thermal degradation temperature and charred residue at 700 °C of composite fibres were lower than those of the pure PET fibres, due to the thermal instability of LA. The MCC tests showed that there were two peaks of heat release rate, which corresponded respectively to combustion of LA and PET in the electrospun composite fibres. It could be also found that the first peak increased and the second peak decreased with increasing LA content in composite fibres.