Study on Structural Deformation and Performance of Polypropylene Spherulite Prepared by Uniaxial Compression Processing

Mechanical properties have close relation with microstructure. Based on orientation of the molecule chain in fiber, they show a rapid increase in tensile properties. Nevertheless, block materials mainly gain rise of mechanical properties by blend or composite, it is hardly proposed on the self-reinforced materials by optimizing the microstructure. In this paper, a strengthening of PP was gained by uniaxial compression through small deformation of spherulite. A series of measurements were applied, including tensile test, polarizing optical microscope (POM) and differential scanning calorimeter (DSC). The results show that the tensile properties of polypropylene (PP) have a rapid rise. POM suggestes that the spherulite has deformed into ellipsoid even belt along the orientation of sample of PP, which plays an important role in self-reinforcing of PP. And the initial melt point displayed by DSC slightly decreases because of the partial ruptures of crystal phase.