β成核剂对聚丙烯发泡材料的结晶行为和发泡性能的影响  

Effect of β Nucleating Agent on the Crystallization Behaviors and Foaming Properties of PP Foams

作　　者：陈逸新 曹贤武 

机构地区：[1]华南理工大学聚合物成型加工工程教育部重点实验室,广东广州510640

出　　处：《塑料工业》2016年第3期63-68,共6页China Plastics Industry

摘　　要：在聚丙烯(PP)中加入β成核剂(TMB-5),以超临界二氧化碳(CO2)作为发泡剂,用高压发泡釜对其进行间歇发泡。研究β成核剂用量、饱和温度、饱和压力对β成核/PP发泡材料的结晶和发泡性能的影响。结果表明,β成核剂有效促进了β晶的形成,发泡材料中β晶相对含量最高可达到92.4%,但增大饱和压力却会抑制β晶产生。β成核剂同时起到异相成核作用,使泡孔成核更容易,制得的样品发泡性能较好。另外,饱和温度的升高会使PP熔体强度降低,导致泡孔的尺寸增大、密度减小;而随着饱和温度降低,饱和压力升高,气体在熔体中的溶解度增大,泡孔成核数量增多,使泡孔密度增大、泡孔尺寸减小。饱和压力为22 MPa时,泡孔密度可达2.72×108个/cm3。Polypropylene （PP） was blended with β nucleating agent, and the compounds were foamed in a high pressure vessel using supercritical carbon dioxide as physical blowing agent. The effect of β nucleating agent content, saturation temperature and saturation pressure on the crystallization behaviors and foaming properties were investigated. The results showed that： β nucleating agent can effectively promote the formation of β-crystals, and the relative content of β-crystals could reach 90%, but higher pressure would lead to lower content of,β-crystals. Ceils nucleation becomes easier and the foaming properties are improved for β nucleating agent plays a part in heterogeneous nucleation. In addition, smaller cell size and higher cell density could be obtained when using higher saturation pressure and lower saturation temperature. Because, the gas solubility in PP melt is increased, which leads to a large number of cell nuclei. When the saturation pressure is 22 MPa, the cell density reaches 2.72×108cells/cm3.

关 键 词：聚丙烯泡沫材料 Β成核剂 超临界二氧化碳 结晶行为 发泡性能 

分 类 号：TQ328[化学工程—合成树脂塑料工业]