Polyvinyl chloride (PVC) and nanosilicon dioxide (nano‐SiO₂) were blended with neat polypropylene (PP) to improve its flame retardancy and cellular foam structure, and the dispersal effects of PVC and nano‐SiO₂ and the foaming effect of the PP/PVC composites were investigated. PP/PVC samples with different compositions and foaming degrees were first fabricated by conventional injection molding with and without a blowing agent. Tensile testing, differential scanning calorimetry, scanning electron microscopy, limiting oxygen index testing, and vertical burn testing were used to study the mechanical properties, thermal features, microstructures, and flame‐retardant properties of the molded samples, and the samples with different degrees of foaming were compared. The results suggest that the foaming process facilitates the dispersion of PVC and nano‐SiO₂, while the presence of PVC and nano‐SiO₂ improves the foamability of PP. A method for a gas‐assisted dispersion technology to control the foaming process was hence proposed. Considering that the mechanical properties of PP/PVC could be retained with satisfactory flame retardancy and weight loss, convenient processing, and low‐cost materials; the technology presented can be directly applied for lightweight engineering and the manufacture of fire‐resistant material and can act as a reference for other micro‐nano processing involving the dispersion of particles. POLYM. ENG. SCI., 60:524–534, 2020. © 2019 Society of Plastics Engineers

中文翻译：

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在控制的发泡过程中使用气体辅助分散法改善PP / PVC复合材料中微纳米颗粒的分散性

将聚氯乙烯（PVC）和纳米二氧化硅（nano-SiO ₂）与纯聚丙烯（PP）共混以提高其阻燃性和多孔泡沫结构，以及PVC和纳米SiO ₂的分散效果并研究了PP / PVC复合材料的发泡效果。首先使用和不使用发泡剂的常规注塑成型方法来制备具有不同组成和发泡度的PP / PVC样品。拉伸测试，差示扫描量热法，扫描电子显微镜，极限氧指数测试和垂直燃烧测试用于研究模塑样品以及不同程度的样品的机械性能，热性能，微观结构和阻燃性能。比较起泡。结果表明，在发泡过程有利于PVC和纳米二氧化硅的分散₂，而PVC和存在纳米的SiO ₂改善PP的发泡性。因此提出了一种气体辅助分散技术来控制发泡过程的方法。考虑到可以保持PP / PVC的机械性能，并具有令人满意的阻燃性和重量减轻，方便的加工以及低成本的材料；所展示的技术可直接应用于轻型工程和耐火材料的制造，并可作为涉及颗粒分散的其他微纳米加工的参考。POLYM。ENG。SCI。，60：524–534，2020.©2019塑料工程师协会