Microcellular Foam Processing of Different PP Blending

Polypropylene(PP) had poor foamability because of its low melt strength.Two different PP resins were blended to improve the foamability and the effect of material properties on the cell morphology was investigated.Experimental results showed that neat PP couldn't be well microcellular foamed at all foaming temperature.When two different PP were bended and microcellular foamed,the cellular structure was improved.In contract to the blend of two PP with similar melting point and viscosity,the blend by adding a PP with lower melting point and viscosity and a PP with a higher melting point and viscosity could be produced microcellular foam with fine cellular structure.The effect of the blend ratio on the cell morphology was investigated,and the vibration principle of the cellular structure was analyzed in respects of the melt viscoelastic property and crystallinity.