Preparation and Properties of Polyacrylonitrile Fiber/Binary of Fatty Acids Composites as Phase Change Materials

Abstract

A new kind of form-stable polyacrylonitrile fiber/binary of fatty acids composites as phase change materials was prepared by a solution blending process. In this material, the binary system between stearic acid and lauric acid with different components was served as latent heat storage material and polyacrylonitrile as the supporting material, N,N-dimethylformamide as solvent. Phase change temperature and latent heat and the thermal stability of the polyacrylonitrile/binary of fatty acids composites were characterized using differential scanning calorimetry. The structure, crystalline morphology, surface morphology, and thermal insulation properties of the polyacrylonitrile/binary of fatty acids composites were investigated using Fourier transformation infrared spectroscope, polarizing optical microscopy, scanning electron microscope, and temperature-recording instrument. The Fourier transformation infrared results showed that polyacrylonitrile and binary of fatty acids were combined by intermolecular forces. The differential scanning calorimetry results indicated that polyacrylonitrile/binary of fatty acids composites had high latent heat storage capacity of more than 135.8 J/g, the phase transition temperature was about 25°C. The photograph of polarizing optical microscopy and scanning electron microscope suggested that stearic acid and lauric acid were homogeneous distribution in the polyacrylonitrile matrix; Cooling curve of polyacrylonitrile/binary of fatty acids composites showed that its soaking time was continued for about 17.7 minutes, and the thermal insulation properties remain unchanged after more than once cycling. The best process condition was obtained by the soaking time and orthogonal experiment.