A kind of magnetic poly (lactic acid) (PLA) melt blown nonwoven fabric (MB) was fabricated by the introduction of ferroferric oxide (Fe3O4) nanoparticles to improve its air filtration performances. In view of the poor compatibility of two components, the poly (L-lactic acid) (PLLA) molecular chains was firstly grafted onto the Fe3O4 nanoparticles surface via the ring opening polymerization (ROP). Then, PLA/Fe3O4-g-PLLA composite masterbatches with different mass ratios were prepared by melt-blending method and processed into the corresponding composite MB. The structures and performances of PLA/Fe3O4-g-PLLA composite masterbatches and their MB were investigated. The results showed that the addition of Fe3O4-g-PLLA nanohybrids hardly influenced the glass transition, cold crystallization and melting behaviors of the composite masterbatches. Though the melt fluidity of the composite masterbatches reduced with the Fe3O4-g-PLLA content increasing, the composite masterbatches still could present the appropriate processability in the range of 210°C to 230°C. Fe3O4-g-PLLA could be uniformly dispersed in PLA matrix and had a good interfacial compatibility with the matrix. Compared with pure PLA MB, the fiber surface of the composite MB became slightly rough, the pore size and distribution of the fiber web increased. The addition of Fe3O4-g-PLLA endowed PLA MB with magnetism. With the increasing of Fe3O4-g-PLLA content, the air permeability of the composite MB was improved and their filtration resistance obviously reduced. When the content of Fe3O4-g-PLLA was 0.5 wt%, the filtration efficiency of the composite MB reached the maximum. Moreover, the composite MB have higher longitudinal tensile strength and elongation at break than those of pure PLA MB.

中文翻译：

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用于空气过滤的磁性 PLA/Fe3O4-g-PLLA 复合熔喷非织造布的制备与表征

通过引入四氧化三铁 (Fe3O4) 纳米粒子制备了一种磁性聚乳酸 (PLA) 熔喷非织造布 (MB) 以提高其空气过滤性能。鉴于两种组分的相容性较差，首先通过开环聚合（ROP）将聚（L-乳酸）（PLLA）分子链接枝到 Fe3O4 纳米粒子表面。然后，采用熔融共混法制备不同质量比的PLA/Fe3O4-g-PLLA复合母料，并加工成相应的复合MB。研究了 PLA/Fe3O4-g-PLLA 复合母料及其 MB 的结构和性能。结果表明，Fe3O4-g-PLLA纳米杂化物的加入几乎不影响复合母料的玻璃化转变、冷结晶和熔融行为。尽管复合母料的熔体流动性随着Fe3O4-g-PLLA含量的增加而降低，但复合母料在210℃～230℃范围内仍能表现出合适的加工性能。Fe3O4-g-PLLA能够均匀地分散在PLA基体中并与基体具有良好的界面相容性。与纯PLA MB相比，复合MB的纤维表面变得略微粗糙，纤维网的孔径和分布增加。Fe3O4-g-PLLA 的加入赋予了 PLA MB 磁性。随着Fe3O4-g-PLLA含量的增加，复合MB的透气性提高，过滤阻力明显降低。当Fe3O4-g-PLLA的含量为0.5wt%时，复合MB的过滤效率达到最大值。而且，