Morphology, thermal and mechanical properties of electrospun polyvinylidene/polyethylene glycol composite nanofibers as form-stabilized phase change materials

Abstract Polyvinylidene fluoride (PVDF)/polyethylene glycol (PEG) form-stabilized composite phase change nanofibers with various mass percentage of PEG1000 (with average molecular weight of 1000) loadings were fabricated by electrospinning technique, in which PEG was served as phase change material (PCM) and PVDF as the supporting matrix to afford a mechanically strong structure. Effect of PEG1000 content on nanofiber morphology, phase transition properties, thermal stability, thermal energy storage and release performance, and mechanical properties were studied experimentally. The results showed that the incorporation of PEG1000 improved the spinning solution viscosity and high mass fraction of PEG1000 in the nanofibers led to decreased fiber diameter and melting temperature, and higher latent heat of fusion. In addition, mechanical test revealed that the fracture elongation of the electrospun PVDF/PEG composite nanofibrous membranes were initially increased with unobvious tensile strength changes, while the value of the elongation would decrease, and the tensile strength increase as the mass ratio of PVDF/PEG lower to 1:1. Furthermore, the melting temperature and maximum latent heat for PVDF/PEG were determined from DSC measurement as 51.8 °C, and 73.3 J/g, when the mass radio of PVDF/PEG was 1:1 (w/w), which was suitable utilized for thermo-regulating textiles or in heat storage devices.