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共混改性是改善聚丙烯(PP)发泡性能的一种有效方法。以不同组分比的PP/高密度聚乙烯(HDPE)共混体系为研究对象,用扫描电镜对发泡样品的泡孔结构进行表征,研究加工条件对泡孔结构的影响。结果表明:向PP中加入HDPE可改善泡孔结构,与饱和温度为120℃相比,饱和温度在140℃时,得到泡孔直径更小,泡孔密度更大,泡孔分布更均匀的复合物。稳定温度在170℃时的泡孔结构明显优于稳定温度在179℃时的泡孔结构,并非压降速率越大得到的泡孔结构越理想,当压降速率过大时,泡孔容易合并或塌陷。
Blending modification is an effective way to improve the foaming properties of polypropylene (PP). The different ratios of PP / HDPE blends were used as the research object. The cell structure of foamed samples was characterized by SEM, and the influence of processing conditions on cell structure was studied. The results showed that the addition of HDPE to PP could improve the cell structure. Compared with the saturated temperature of 120 ℃, when the saturation temperature was 140 ℃, the cell diameter was smaller, the cell density was higher and the cell distribution was more uniform Things. The cell structure at a stable temperature of 170 ℃ is obviously better than that of the cell at a stable temperature of 179 ℃. The better the cell structure is, the more the pressure drop rate is. Or collapse.