Novel nucleating agents for polypropylene and modifier of its physical-mechanical properties

Abstract

© 2020 Elsevier Ltd In this paper, we demonstrate that dicalcium salt of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) can be used as a component of nucleating agents for isotactic polypropylene (iPP) - one of the most widely used commercial polymers. Based on dicalcium HEDP salt novel nucleators show high efficiency in the nucleation of iPP α-crystals. At a concentration of 0.25 wt% the nucleators demonstrate an increase in crystallinity (+ 1.5 % in composition with calcium stearate and + 4% - with zinc stearate). When the dicalcium HEDP salt based nucleator is added to the iPP, the flexural modulus increases by 8–12 %. Assumptions are suggested about the mechanism of action of the new nucleator, based on its core-shell structure. The main component of the nucleating agent, the dicalcium HEDP salt, is synthesized by the one-step reaction in a non-toxic aqueous medium with commercially available reagents. The synthetic protocol gives a finely friable product that does not require further grinding. The synthesis is cheap and environmentally friendly since only deionized water is used as a solvent.