Preparation and properties of poly (lactic acid)/magnetic Fe3O4 composites and nonwovens

Abstract

To develop degradable and magnetic PLA-based melt-blown (MB) nonwoven materials for air filtration applications, poly (lactic acid) (PLA)/magnetic Fe₃O₄ (PLA/Fe₃O₄) MB nonwovens were obtained by melt blowing using the PLA/Fe₃O₄ composites with different components prepared by melt-mixing as the masterbatch. The crystallization and melting behavior of the composites were examined with differential scanning calorimetry (DSC). Although the results showed that the Fe₃O₄ particles obviously hindered the cold crystallization process of PLA and the relative crystallinity degree of the composites decreased due to the addition of Fe₃O₄; there was no overall change in the crystal structure of PLA according to the wide-angle X-ray diffraction (XRD). Thermogravimetric analysis (TGA) and dynamic rheological measurements demonstrated that the introduction of Fe₃O₄ reduced the thermal stability of PLA. The effect of Fe₃O₄ particles on the morphology of the PLA/Fe₃O₄ composites and MB nonwovens was characterized by scanning electron microscopy (SEM). It revealed that the Fe₃O₄ particles were dispersed in a PLA mixture with the “sea-island” structure, and the addition of Fe₃O₄ particles also made the fiber surface rough and the nonwoven web turned fluffy to some extent. The magnetic properties and filtration performance of the MB nonwovens were also investigated in detail.