Abstract: We report a facile melt radical grafting reaction method to fabricate covalent grafted polypropylene(PP)/carbon nanotubes(CNTs) nanocomposites using 2,5-dimethyl-2,5(tert-butylperoxy) hexane peroxide(DHBP) to induce the radical and using tetramethylthiuram(TMTD) to control radical grafting reaction. The covalent grafting reaction was characterized by Raman spectroscopy and TEM. The crystallization, thermal and mechanical properties of the composites were studied. Compared with noncovalent grafted PP/CNTs composites and PP, the covalent grafted nanocomposites showed increased crystallization temperatures(2.6 and 12.0 ℃, respectively) and thermal decomposition temperatures(6.4 and 34.8 ℃, respectively), an increased tensile strength and tensile modulus to a little extent, and increased notched impact strength by 56.7% and 58.1%, respectively.

Key words: Polypropylene, Carbon nanotubes, Nanocomposites, Radical grafting