Electrospun PMMA fibers blended with core-shell PCM/PS microspheres for thermal regulating applications

Phase changing materials (PCMs) have been widely investigated because of their unique properties and applications. In recent years, PCMs have been embedded into polymer fibers for thermal regulating purposes. The PCM-containing polymer fibers, however, usually suffer the leakage problem because PCMs are not covered well by polymers in fibers. To solve this problem, in this study, we develop a facile strategy to fabricate PCM-containing polymer fibers without the leakage problem. The PCM/polystyrene (PS) core-shell microspheres are first prepared by suspension polymerization, in which n-hexadecane is used as the PCM. By blending the PCM/PS microspheres into polymethyl methacrylate (PMMA) solutions, The PMMA fibers blended with core-shell PCM/PS microspheres can be prepared via electrospinning. Acetic acid is chosen as the solvent, which can selectively dissolve PMMA and cannot dissolve PS. Therefore, the morphologies of the core-shell PCM/PS microspheres can be maintained during the electrospinning processes. The microspheres and fibers are characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Thermal imaging results demonstrate that the PCM-containing fibers can effectively regulate temperatures and fibers with higher contents of PCM exhibit better thermal regulating behaviors. Repeated thermal regulating experiments are also conducted for up to 4 cycles.