驻极体-增塑剂复合改性聚乳酸熔喷非织造材料的制备及性能

分别采用无机纳米SiO₂或一种商用有机助剂（O-electret）作为驻极体改性剂，并通过引入环氧大豆油（ESO）和聚乙二醇（PEG）作为增塑剂对聚乳酸（PLA）进行了复合改性，在传统工业熔喷生产线上制备了具有可生物降解特性的驻极体-增塑剂/PLA熔喷非织造复合材料。利用转矩流变仪和熔融指数仪测试了复合改性PLA切片的流动性，发现加入ESO和PEG能使熔融指数提高到110 g/10 min。利用DMA测试了驻极体-增塑剂/PLA熔喷非织造复合材料的力学性能，发现采用增塑剂改性后能显著提高材料的拉伸强度和塑性。利用滤料综合性能测试台测试了的驻极体-增塑剂/PLA熔喷非织造复合材料的过滤性能，结果显示，驻极改性能够使其过滤PM2.5的效率提高至86%及以上。利用SEM研究了驻极体-增塑剂/PLA熔喷非织造复合材料表面的微观形貌，结果表明，采用驻极体改性后，细纤维的比例显著增加；采用增塑剂改性使纤维更细更长，纤维间交错更加复杂。 

Preparation and characterization of poly(lactic acid) meltblown nonwovens modified by electrets and co-plasticizers

The Compound modifications of poly(lactic acid)(PLA) were conducted by using nano SiO₂ or one organic matter as the electrets (O-electret), and using epoxy soybean oil (ESO) and poly(ethylene) (PEG) as the combined plasticizers, respectively. Then the biodegradable electret-plasticizer/PLA meltblown nonwoven composites were manufactured on a commercial meltblown production line. The melt flowability of modified PLA chips was tested by using a torque rheometer and a melt flow index (MFI) instrument. It is found that addition of ESO and PEG improves the MFI to 110 g/10 min. The mechanical properties of meltblown nonwoven composite were tested by DMA. The relevant results indicate that the strength and plasticity of meltblown nonwoven composites can be remarkably enhanced after being modified by plasticizers. Filter media testing platform was used to evaluate the filtration performance of electret-plasticizer/PLA meltblown nonwoven composites. It is found that introduction of electret could improve the PM2.5 filtration efficiency of that to 86% or more. SEM observations were eventually employed to study the micromorphology of the nonwoven composites, the result shows that the ratio of fine fibers within the PLA meltblown nonwoven has been increased notably after electret modification, and with the help of plasticizers such microscale fibers became relatively longer and finer, hence the interlacement of these fibers turned more complex.