The research on aggregation structure of PP materials under different condition and the influence on mechanical properties

In this article, the study of the aggregation structure of PP material with the IAS4 Image Analysis System is reported. The result indicates that the morphology of spherulite or filling particle in the matrix of crystalline polymer can be quantitatively described by the IAS4 Image Analysis System. Through the measurement of the aggregation structure, the transformation of mechanical properties was explained. With the increase of filling quantity of nucleating agent, the crystallinity (Xc) tends to increase, the spherulite size (Dn) and its distribution (Cd) tends towards decline. The different heat treatment technology influenced only the crystallinity but not the spherulite size or its distribution. The effects of Xc, Dn and Cd on mechanical properties were investigated. It was shown that, with the decrease of Xc, Dn or Cd, the notch impact strength increases. To the PP/talc composite, the aggregation of talc particle has relation with the original size of particle, filling quantity and the surface treatment level. With the decrease of particle size or uniform distribution, the notch impact strength rises up.