本征特性对聚苯乙烯及聚丙烯发泡行为的影响

以化学发泡注塑成型技术为主线,在二次开模条件下制备微发泡聚苯乙烯（PS）及微发泡聚丙烯（PP）;通过流变性、加工性分析了树脂本征特性对PS及PP发泡行为的影响。结果表明：本征特性对气泡的长大和定型过程、气体扩散具有明显的影响;熔体强度越高的材料,阻碍泡孔长大的趋势越明显,所得到的泡孔越细小而均匀;PS具有合适的熔体强度和熔体流动速率（MFR）,发泡质量较理想,泡孔直径和泡孔密度分别为41.4μm、8.7×106个/cm3;PP（K9026）熔体强度较低,而熔体流动速率过大,发泡质量明显降低,泡孔直径和泡孔密度分别为65.94μm、5.82×105个/cm3。

The Effect of Intrinsic Characteristic of PS and Polyolefin on Its Foaming Behavior

By taking chemical foaming injection molding technology as main line,the microcellular foam polystrene（PS） material and microcellular foam polyproprene material were made under the condition of twice-open mold.By means of rheological property and process-ability,the effect of different intrinsic characteristic on foaming behavior was analyzed for foamed polystrene and polyproprene materials.The results showed that intrinsic characteristic have obvious effect to growth and setting process of cell,the higher melt strength,the bigger hindering air bubble growth action.PS materials have ideal melt strength and melt index,so which has ideal foaming quality to prepare microcellular foam material,the cell diameter is 41.4μm,cell density is 8.7×106 number/cm3.Because of low melt strength and too high melt index of PP（K9026）,its cell diameter is 65.94 μm,cell density is 5.82×105 number/cm3,which foam quality is significantly lower than that of PS.