Study On Preparation And Properties Of Electrospun LA-SA/PAN Composite Phase Change Fibers

The theory and application research of the intelligent fibers has received extensive attention. As one of the intelligent fibers, self-adapted phase change fibers are also widely studied. To get the thermo-regulated fibers, one way is to prepare the form-stable phase change materials（FSPCMs） whose frame material is polymer and phase change range is room temperature. In this paper, to make full use of the advantages of phase change materials and the electrostatic spinning technology, the lauric acid（PLA） and stearic acid（SA） were taken as binary fatty acid eutectic, and the polyacrylonitrile（PAN） was taken as supporting material.The formability of LA-SA/PAN ultrafine composite phase change fibers was studied.The PAN fibers was fabricated using the technique of electrospinning. The effects of PAN concentration, spinning voltage, injection rate and receiving distance on the PAN fiber morphology were studied. To measure the average diameter of the fibers, SEM photos and image analysis software Smile-View were used. The results showed that the optimal spinning parameters were solution concentration of 12wt%, voltage of 15 kV, spinning rate of 1mL/ h and receiving distance of 20 cm.Based on the above results, the LA-SA/PAN composite form-stable phase change fibers were successfully prepared by the electro-spunning method. The effects of different mass ratio of LA-SA and PAN and TiO₂ addition on morphological structures, mechanical properties and thermal energy storage property of the composite phase change fibers were studied. The SEM images showed that with the increase of LA-SA amount, the grooves or ridges on the surface of the composite fibers became more obvious. After the addition of 0.5wt% TiO₂, the spinnability was good and the fiber membrane had uniform thickness when the mass ratio of LA-SA was 0.5:1 and 0.7:1. The DSC results indicated that the phase transition temperatures of LA-SA/PAN fibers ranged from 33.3℃ to 38.9℃, which was close to the phase transition temperatures of（LA-SA）binary fatty acid eutectic. While their heat enthalpies（30.75⁸8.08J/g）were much lower than the（LA-SA）binary fatty acid eutectic（135.1J/g）. The DSC thermal cycling test suggested that the thermal properties of the LA-SA/PAN/TiO₂ composite fiber canbe maintained after repeated thermal cycle treatment and it was a reversible phase change material.The TG results showed that the thermal weight loss of the composite fibers increased with the increase of the（LA-SA）binary fatty acid eutectic, but it good thermal stability during the phase transition temperature range, and the TiO₂ in the fibers could increase the thermal stability. The mechanical tests showed that the strength of the fiber membrane was 1.936 MPa when the mixture ratio of LA-SA and PAN was 0.7:1.The composite phase change fibers have great potential applications in textiles and clothing field, and subsequent development remains to be studied.