Abstract:

Low-density polyethylene (LDPE) has excellent corrosion resistance, abrasion resistance and hydrophobicity, but it has poor processing fluidity and difficulty in melt fiberization. Polyethylene wax (PEW) was used as an additive and blended with LDPE to prepare high melt index spinning raw materials with excellent processing performance. In this paper, the fluidity and crystallization properties of LDPE/PEW blends under different raw material ratios were studied, LDPE/PEW nonwovens were prepared by melt-blown process, and the microscopic morphology, fiber diameter, waterproof and moisture permeability and filtration performance of the nonwovens were studied and analyzed. The results showed that with the increase of PEW content, the melt flow index of the blend continued to increase. The melt indicated good fluidity and spinnability, and the diameter of the melt-blown fiber was significantly refined. The average fiber diameter could reached as little as 5.7μm. When the mass fraction of PEW was 70%, the water contact angle of the melt-blown nonwovens was 144.8°, showing excellent hydrophobic characteristics. At the flow rate of 32L/min, the filtration performance of the nonwoven fabric was 80.67% and the filtration resistance was only 23.1Pa, indicating good high efficiency and low resistance characteristics.

Key words: low-density polyethylene, composites, polymer processing, filtration, microfiber

摘要：

低密度聚乙烯（LDPE）具备优良的耐腐蚀性、耐磨性和疏水性，但加工流动性差，熔体成纤困难。以聚乙烯蜡（PEW）为添加剂，与LDPE共混改性后可制备出具有优异加工性能的高熔融指数纺丝原料。本文研究了不同原料配比下LDPE/PEW共混物的流动性能和热结晶性能，进一步采用熔喷工艺制备了LDPE/PEW非织造布，并对非织造布的微观形貌、纤维直径、防水透湿性能和过滤性能进行了研究和分析。结果表明，随着PEW含量的增加，共混物的熔融指数不断提升，熔体表现出良好的流动性和可纺性，熔喷纤维的直径显著细化，纤维平均直径最小可达5.7μm。在PEW的质量分数为70%时，熔喷非织造布的水接触角为144.8°，呈现优异的疏水性能。在32L/min测试流量下，非织造布的过滤性能为80.67%，滤阻仅为23.1Pa，表现出良好的高效低阻特性。

关键词: 低密度聚乙烯, 复合材料, 聚合物加工, 过滤, 超细纤维