title: 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.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Céline
authors.initials: C
authors.lastname: Shepherd
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Emina
authors.initials: E
authors.lastname: Hadzifejzovic
authors.affiliation: School of Engineering, Cardiff University , The Queen's Buildings, The Parade, Cardiff CF24 3AA, United Kingdom.
authors.forename: Fatma
authors.initials: F
authors.lastname: Shkal
authors.affiliation: Department of Materials, University of Oxford , Parks Road, OX1 3PH Oxford, United Kingdom.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Jurkschat
authors.affiliation: Department of Materials, University of Oxford , Parks Road, OX1 3PH Oxford, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Moghal
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Emily M
authors.initials: EM
authors.lastname: Parker
authors.affiliation: Department of Chemical and Biomolecular Engineering, School of Energy Science and Technology, Vidyasirimedhi Institute of Science and Technology , Rayong 21210, Thailand.
authors.forename: Montree
authors.initials: M
authors.lastname: Sawangphruk
authors.affiliation: School of Engineering, Cardiff University , The Queen's Buildings, The Parade, Cardiff CF24 3AA, United Kingdom.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Slocombe
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: John S
authors.initials: JS
authors.lastname: Foord
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Moloney