New Approaches for the Interpretation of the Structure and Phase Transitions in Nanocomposites Based on Modified Polyolefins and Technical Carbon

Abstract

The results of the investigation of the thermomechanical characteristics of maleinized polyolefine-based nanocomposite materials with different carbon black content are presented. The high density polyethylene, low density polyethylene and polypropylene were used as polyolefins. Highly structured amorphous carbon black of the Printex XE 2B brand with a nanoparticle size of 20 nm, introduced into the composition of the polyolefin in an amount of 1.0–20 wt%, was used as technical carbon. To improve the compatibility of polyolefins with technical carbon, a compatibilizer was used – high-density polyethylene graft copolymer with 5-6 wt% maleic anhydride (PEMA) brand Exxelor PO1040 and polypropylene graft copolymer with 5-6 wt% maleic anhydride (PPMA) brand Exxelor PO1020. The compatibilizer was introduced into the composition of polyolefins in the amount of 2.0 wt%. An electron microscopic, derivatographic and X-ray diffraction analysis of nanocomposites with different technical carbon content was carried out. Thermomechanical studies were carried out on a Kanavets instrument. It was found that with an increase in the content of technical carbon within 1.0, 5.0, 10, 20 wt%, the regularity of change in the thermomechanical curves undergoes significant changes. At a technical carbon concentration of 10 and 20 wt%, an area as a plateau appears on the thermomechanical curves. The most thermally stable plateau appeared for nanocomposites based on maleized LDPE* and PP* with 20 wt% technical carbon content. New scientific approaches are presented for interpreting the discovered regularities, taking into account modern theoretical concepts of the supramolecular crystal structure of nanocomposites and the interfacial amorphous region.