Effect of sulfur phase transition on polypropylene crystallization

ABSTRACT

The Polypropylene (PP) crystals can be regulated by inorganic additive. In this work, sulfur was blended with PP by dynamical in-situ dispersion to obtain good dispersion and refinement; meanwhile, during the non-isothermal crystallization of PP, the phase state of the dispersed sulfur phase changed from the liquid to the supercooled state, affecting the crystalline morphology and crystallization behavior of PP. The results showed that amorphous sulfur particles were present in the PP spherulites, which was obviously different from the traditional crystal morphology. The crystallization rate of the blend is found to increase with smaller sulfur content and due to the occurrence of the sulfur phase change; the crystallization activation energy are less than that of pure PP.

Graphical Abstract

KEYWORDS:

• Polypropylene
• sulfur
• crystallization
• phase behavior
• activation energy