丙烯基纳微米弹性过滤材料的熔喷成型及其过滤性能

为增强聚丙烯(PP)熔喷非织造材料的弹性以解决其用于过滤材料脆性大、抗拉性差的不足,以共混熔喷法制备了以丙烯基弹性体(PBE)为增强基的PBE/PP基纳微米纤维材料,测试了PBE/PP共混体系的热性能和熔体流变特性,分析了PBE质量分数和熔喷工艺对样品弹性和过滤性能的影响。结果表明,随着PBE用量增加到85%,该共混体系的熔融峰值从173.6 ℃降低到165.1 ℃,结晶度从39.0% 逐渐降低到9.8%;纤维直径在0.4~16 μm 之间呈现二值化分布特性,并且细纤维穿插与粗纤维间以组成立体迂曲的“嵌入”形态;随着PBE的质量分数增大到85%,纤维直径小于2 μm的纤维数量占比增大到68.3%,纵、横向弹性回复率分别增大到81.8%和79.1%,进而样品的过滤效率增大约1.8 倍,静水压增大到 4 699.6 Pa。

Filtrations of propylene-based micro-nano elastic filters via melt blowing process

In order to enhance the elasticity of polypropylene (PP) melt blown nonwovens to solve brittleness and poor tensile strength when used as filters, samples of PBE/PP micro-nano fibrous materials reinforced with propylene-based elastomer (PBE) were prepared through the blending melt blowing process. The thermal properties and rheological properties of the PBE/PP blends were tested and the effects of PBE mass ratio and melt blowing process parameters on elasticity and filtration properties of the samples were studied. The results show that the melting peak of the blends decreases from 173.6 ℃ to 165.1 ℃ and the crystallinity gradually decreases from 39.0% to 9.8% as the PBE mass ratio is increased to 85%. Scanning electron microscope (SEM) images show that the fiber diameter (d_f) distribution indicates binary feature in the range of 0.4-16 μm. The fine fibers are interspersed with the coarse ones to form a three-dimensional tortuous "embed" network. As the mass fraction of PBE increases to 85%, the proportion of the fine fibers with d_f of less than 2 μm increases to 68.3%, and the elastic recovery rate of the samples in the machine direction and cross direction increases to 81.8% and 79.1%, respectively. The filtration efficiency increases by about 1.8 times, and the hydrostatic pressure resistance increases to 4 699.6 Pa.