Abstract:

Paraffin with a melting temperature in the range of 28 – 59 °C was used in the research. It was melt-blended with medium density polypropylene (PP). Thermal properties of the -paraffin and the temperature range at which its effective phase transitions proceed, crucial for their use as PCM, were examined by means of differential scanning calorimetry (DSC). It is indicated that employing such a temperature range under dynamic conditions is a much better characteristic for the application of materials than merely using the sharp melting temperature and total energy of the phase transition.  Blends of PP with a content of 20 and 30 wt% of paraffin were DSC-analysed in respect of (a) morphology with the use of an optical microscope and scanning electron microscopy (SEM), and (b) rheology with the use of a plastometer to measure the melt flow index (MFI) at 180, 200 and 230 °C. In the next part this work  the possibilities of producing nonwovens from various blends of PP/paraffin by melt-blown technique were examined. The nonwovens produced were characterised metrologically according to industry standards, and their thermal properties by DSC were studied, and the Temperature Regulation Factor determined (TRF). The morphology of the non-woven and single fibers  was also studied by technique SME.