Preparation and application of low temperature protection materials by Na2SO4·10H2O/PS phase change microcapsules

Abstract

To find the phase change microcapsule material (MEPCM) with suitable temperature and high heat storage energy. The phase change microcapsules with sodium sulfate decahydrate (Na2SO4·10H2O) as core material and polystyrene (PS) as wall material were prepared by emulsion polymerization. The microcapsule is fixed on the cloth of the overalls by coating method, and the thermoregulation fabric is obtained. The microcapsules were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and infrared spectroscopy (FTIR). Fabrics are tested for durability, air permeability and temperature control. The DSC results show that the Tc and Tm of Na2SO4·10H2O/PS microcapsules are 26.0 °C and 58.0 °C, respectively, and the ΔHc and ΔHm are 64.0 J g−1 and 121.1 J g−1, respectively. The TG results show that the first weight loss temperature range is 104.1 ∼136.7 °C, and the second weight loss temperature range is 395.5 ∼434.6 °C. The infrared spectral characteristic peaks of microcapsules include all the characteristic peaks of Na2SO4·10H2O and PS. In the range of microcapsule phase transition temperature, the cloth treated with 0.5 g MEPCM and 1.5 g MEPCM delayed the temperature change by 16.0 ∼23.0 °C and 10.0 ∼18.0 °C, respectively, compared with the blank cloth. The fabric treated with 0.5 g microcapsules was subjected to 100 and 300 heating/cooling cycles. Compared with before and after the cycles, the fabric after thermal shock cycles showed a 4.15% and 3.56% reduction in delayed temperature changes rate in a rising and falling temperature environment. Therefore, Na2SO4·10H2O/PS microcapsule material can achieve the goal of heat storage and energy storage, and can be used as a low-temperature operation protection material.