Relationship between the Long Period and the Mechanical Properties of Recycled Polypropylene

Waste polymer is thought to show poor mechanical property because of chemical degradation. However, from our recent studies, we have found that the main reason of the poor mechanical property is physically degraded and we can regenerate the mechanical property as virgin level. And this physical degradation is thought to be caused from crystalline inner structure. In this study, we prepared various samples by changing molding and heat treatment conditions. We also evaluated the relationship between long period and thickness of amorphous layer in the crystal structure by SAXS measurement and mechanical properties by tensile measurement of these samples. From this study, we found good relationship between these properties.