Structure And Propetries Of Fatty Acids/PA6Ultrafine Composite Phase Change Fibers

Reasonable and effective development of new sources of energy as well as improvingworking efficiency is of great significance in easing the growing problem of energy shortage,of which one most important aspect is to store and release energy by specific material’s phasetransition process. Fatty acids have attracted great attention for its large heat storage densityand stable temperature during phase change process. However, some drawbacks such as lowthermal conductivity, amorphous phase change process, easily leak, et.al have restricted itsfurther use. So to resolve these problems and fully develop the energy storage properties ofPCMs, studying on shape-stabilized PCMs is of great importance. The rapid development ofnanotechnology and its wide application in composite material field gives great opportunitiesfor high performance composite PCMs. Electrospinning is an easy and important method toproduce ultrafine composite phase change fibers.In this paper, polyamide6(PA6) was selected as the supporting material and lauric acid(LA) as the phase change material, the LA/PA6ultrafine composite phase change fibers wereprepared by electrospinning, and the influences of carbon nanofibers (CNFs) and carbonnanotubes (CNTs) on the structure, morphology and properties of LA/PA6ultrafine compositephase change fibers were investigated; According to the method of physical adsorption, CAseries fatty acids/PA6ultrafine composite phase change fibers were prepared by usingelectrospun PA6nanofiber membranes to adsorb capric acids (CA) and its binary eutecticfatty acids (e. g. CA-LA, CA-PA and CA-SA), the effects of expanded graphite (EG) on thethermal properties of CA series fatty acids/PA6ultrafine composite phase change fibers wereconsidered. By characterization of field emission scanning electron microscope (FE-SEM),differential scanning calorimeter (DSC), thermogravimetrice (TGA), micro-combustioncalorimeter (MCC) and thermal conductivity test to study on the Surface morphology, thermalenergy storage, thermal stability, flammability and thermal conductivity properties of ultrafinecomposite phase change fibers.The SEM images of LA/PA6/CNFs and LA/PA6/CNTs ultrafine composite phase changefibers revealed that electrospun ultrafine composite phase change fibers have goodmorphology structure; the analysis of DSC, TGA, MCC and thermal conductivity propertiestest showed that ultrafine composite phase change fibers were provided with preferablethermal energy storage properties; the addition of CNFs (or CNTs) enhanced thermal stabilityproperties, decreased flammability properties and improved thermal conductivity properties ofultrafine composite phase change fibers. In addition, the SEM images of CA series fattyacids/PA6/EG ultrafine composite phase change fibers revealed that nanofiber membranesexpanded and fiber diameter increased after absorbing fatty acids; addition of EG increasedthe adsorption quantity of CA series fatty acids adsorbed by PA6nanofiber membranes andenhanced thermal conductivity properties, increased latent heat of ultrafine composite phasechange fibers, however, it had no appreciable influences on the phase transition temperaturesof ultrafine composite phase change fibers.