Thermal energy storage systems based on poly(vinyl chloride) blends

A series of blends of poly(vinyl chloride) (PVC) with: (i) poly(methyl methacrylate) (PMMA), or (ii) polyoxymethylene (POM), with poly(ethylene glycol) (PEG) as a thermal energy storage material, has been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) alone, or coupled with Fourier transform infrared spectroscopy (FTIR). For the blends under investigation it was found that PEG has a significant effect on their thermal properties. It causes the initial decomposition temperatures to increase by about 70 degrees C for PVC/POM blends, a substantial suppression of the volatile products evolution for PVC/PMMA blends, and for both polymer systems an improvement in the surface morphology in terms of uniformity. Based on the radical decomposition schemes of PEG and PVC a possible radical scavenger action was discussed as a reason for greater thermal stability. (C) 1998 Elsevier Science Ltd. All rights reserved.