聚丙烯/超高摩尔质量聚乙烯釜压发泡材料的研究

Study of PP / UHMWPE Bath Foams

以二氧化碳(CO_2)为发泡剂,采用釜内受限发泡的方法制备了超高摩尔质量聚乙烯(UHMWPE)共混改性的聚丙烯(PP)发泡材料。采用旋转流变仪、示差扫描量热仪研究了UHMWPE对PP的流变特性和结晶特性的影响,还通过扫描电子显微镜、万能试验机等探究了共混体系的发泡特性与其发泡材料的静态压缩特性。结果表明,UHMWPE的加入能提高PP的熔体强度,改善其发泡特性。在UHMWPE含量为20%时,得到平均泡孔尺寸最小(8.443μm)及泡孔密度最大(10.566×10~9个/cm^3)的发泡材料;同时共混体系的静态压缩特性与其发泡特性具有直接的关系,泡孔形态更好的发泡材料对应的压缩特性也更好。

Polypropylene （PP） foams modified with ultra-high molecular weight polyethylene （UHMWPE） were prepared through autoclave foaming process using carbon dioxide （CO2 ） as the blowing agent. The influence of UHMWPE on rheological properties and crystallization characteristics of PP were investigated by rotational rheometer and differential scanning electron （DSC）. Furthermore, the foaming properties of PP/UHMWPE blend system and the compression performance of the foaming material were investigated by scanning electron microscope （SEM） , universal testing machine. The results indicate that the addition of UHMWPE can improve the melt strength and foaming properties of PP. The foaming material, whose average cell size is the smallest （8.443μm） and the cell density is maximum （10. 566×10^9cells/ cm3 ） , is obtained when the content of UHMWPE is 20%. The compression performance of the foams has a direct relationship with its foaming properties, and the foaming material with better cell morphology has better compression characteristic also.