New Routes to Functionalize Carbon Black for Polypropylene Nanocomposites

Abstract

Methods for chemical surface functionalization for carbon black (CB) nanoparticles were studied to produce (CB)/polypropylene (PP) nanocomposites with superior electrical and thermal properties. Nanoparticle dispersion is known to directly control the extent to which nanocomposites maximize the unique attributes of their nanoscale fillers. As a result, tailored nanoparticle surface chemistry is a widely utilized method to enhance the interfacial interactions between nanoparticles and polymer matrices, assisting improved filler dispersion. In this work, a rapid chemical functionalization approach using a number of diarylcarbene derivatives, followed by the azo-coupling of substituted diazonium salts, for the covalent introduction of selected functional groups to the CB surface, is reported. Characterization of the modified CB by XPS, TGA, CHN, and ATR-IR collectively confirmed surface functionalization, estimating surface grafting densities of the order of 10(13) and 10(14) molecules/cm(2). Nanocomposites, synthesized by solvent mixing PP with pristine and modified CB, demonstrated macroscopic property changes as a result of the nanoparticle surface functionalization. Pronounced improvements were observed for PP nanocomposites prepared with a dodecyl-terminated diaryl functionalized CB, in which TEM analysis established improved nanofiller dispersion owing to the enhanced CB-PP interfacial interactions in the nanocomposite. Observed dielectric relaxation responses at 20 wt % loading and a reduced percolation threshold realized conductivities of 1.19 × 10(-4) S cm(-1) at 10 wt %, compared to 2.62 × 10(-15) S cm(-1) for pristine CB/PP nanocomposites at the same filler loading. In addition, thermal properties signify an increase in the number of nucleation sites by the raised degree of crystallinity as well as increased melting and crystallization temperatures.

Carbon black reborn: Structure and chemistry for renewable energy harnessing

“…This resulted in the covalent C-C bonding of a variety of aryl units with the CB surface [151,152]. Furthermore, diaryl diazo compounds have also been employed to functionalize MONARCH ® 430 for use in polypropylene nanocomposites [153]. The proposed mechanism for this reaction follows a thermal diazonium coupling reaction through the formation of transient carbene produced by the decomposition of the labile diazo precursor ( Figure 26).…”

Carbon black modified with 4‐hydroxymethylbenzenediazonium salt as filler for phenol‐formaldehyde resins and abrasive tools

“…The exception is nitrogen, which can be observed only in the modified material. The appearance of nitrogen at 399.5 eV (Figure ) is associated with the occurrence of azo bonds between the rings in the aryl layer or between the aryl layer and the surface of the CB . After the modification process on the CB surface, the amount of oxygen also increases.…”

Self‐healing polyurethane nanocomposite films with recoverable surface hydrophobicity

“…Therefore, the modified SiO 2 nanoparticles 7 was obtained by the attachment of perfluoroalkyl groups onto the surface. This was proved to be an convenient approach to chemically introduce organic groups onto inorganic materials, such as SiO 2 , TiO 2 , carbon black, and graphene …”

“…First, several furan‐based monomers were synthesized to prepare polyurethanes, which were subsequently crosslinked with maleimides through the typical DA/rDA reaction. Secondly, perfluoroalkyl diazomethane was synthesized and introduced onto the surface of SiO 2 nanoparticles by carbene insertion approach, which was proved by us to be a short synthetic route with mild reaction conditions, and could be further used to introduce color, fluorescence, biocompatibility, and biocidal properties . Finally, polymer nanocomposite films were prepared by mixing modified SiO 2 nanoparticles with self‐healing polyurethanes, followed by the characterization of their mechanical property and surface performance.…”