Mechanochemically aminated multilayer graphene for carbon/polypropylene graft polymers and nanocomposites

Abstract

The two-stage mechanochemical amination of graphite by dry ball milling of graphite in a planetary ball mill under Ar followed by NH 3 yields aminated multilayer graphene (AMFG) as intermediates for carbon/polymer hybrids and nanocomposites. Opposite to efficient edge-selective graphene functionalization under Ar, CO 2 and N 2 pressure, the onestage ball milling under NH 3 pressure affords rather low N content (<0.5 wt%) and fails to reduce the graphite platelet size. According to DFT (Density Functional Theory) calculations NH 3 exhibits low mobility between graphene layers and forms weak bonds to carbon which impair breakage of carbon bonds. In the two-stage ball-milling of graphite under Ar affords reactive carbon nanoparticles which react with NH 3 in the second stage. With increasing milling duration of the second stage the nitrogen content increases to 3.2 wt%. As verified by XPS (X-ray photoelectron spectroscopy) measurements primary amine groups are formed which couple with various dicarboxylic anhydride groups including maleated PP to produce imidefunctionalized graphene. This is of interest to produce compatibilizers and dispersing agents for carbon/PP nanocomposites exhibiting improved mechanical properties. Two-stage mechanochemistry holds promise for carbon nanoparticle functionalization well beyond amination.

Effect of Nanographite Type on Structure and Mechanical Properties of Hybrid Composites of Poly(ethylene terephthalate) Filled with Short Glass Fibers and Nanographite

“…Nanoscale allotropic forms of carbon with sp 2 -type chemical bonding between atoms-graphene (Gr), nanographite (nG), and carbon nanotubes (CNT)have unique strength, heat, and electrophysical characteristics and are effective modifiers that affect the structure and properties of polymers [1][2][3]. From the practical viewpoint, it is important that multilayer nG particles, as a rule, are not inferior to single-layer Gr in terms of the effectiveness of reinforcing action during polymer filling; therefore, nG is of the greatest practical interest, since it has a significantly lower cost compared to CNTs and graphene [4].…”

Структура И Механические Свойства Полиэтилентерефталата, Наполненного Нанографитом Разного Типа И Коротким Стекловолокном

“…22:678.6 https://doi.org /10.21517/1992-7223-2019-5-6-56-64 ВВЕДЕНИЕ Наноразмерные аллотропные формы углерода с sp 2 -типом химической связи между атомами -графен (Гр), нанографит (нГ) и углеродные нанотрубки (УНТ), обладают уникальными прочностными, тепло-и электрофизическими характеристиками и являются эффективными модификаторами, влияющими на структуру и свойства полимеров [1][2][3]. С практической точки зрения важно, что частицы многослойного нГ по эффективности армирующего действия при наполнении полимеров, как правило, не уступают однослойному Гр, поэтому на-нографит представляет наибольший практический интерес, так как обладает существенно меньшей стоимостью по сравнению с УНТ и графеном [4].…”