Dielectric relaxation of near-percolated carbon nanofiber polypropylene composites

• Tipo: Artigo em Revista Científica Internacional
• Data: 2017

Autores

Paleo, AJ (Autor) Outra; Zille, A (Autor) Outra; Van Hattum, FW (Autor) Outra; Ares Pernas, A (Autor) Outra; Agostinho Moreira, JA (Autor) FCUP

Revista

Título: Physica B: Condensed Matter

Vol. 516

Páginas: 41-47

ISSN: 0921-4526

Editora: Elsevier

Indexação

ISI Web of Knowledge - 6 Citações

Scopus - 7 Citações

Outras Informações

ID Authenticus: P-00M-RGH

DOI: 10.1016/j.physb.2017.04.027

Abstract (EN): In this work, the morphological, structural and dielectric analysis of near-percolated polypropylene (PP) composites containing carbon nanofibers (CNF) processing by melt-mixing are investigated. Whereas the morphological analysis shows that CNF exhibit some tendency to agglomerate within the PP matrix, the structural analysis showed first a general decrease in the intensity of the IR bands as a consequence of the interaction between carbon nanofibers and PP matrix and second an increase of the crystallinity degree of the PP/CNF composites when compared to the pure PP. The dielectric analysis demonstrates enhanced dielectric constants (from 2.97 for neat polymer to 9.7 for 1.9 vol% loaded composites at 200 Hz) and low dielectric losses. Furthermore, the dielectric relaxation for composites with concentrations in the vicinity of percolation is evidenced and well described by the generalized polydispersive Cole-Cole model from which the values of static dielectric constant (epsilon(s)), high frequency dielectric constant ((8 epsilon)), distribution of relaxation time (alpha) and mean relaxation time (tau(o)), are determined, suggesting that this latter analysis constitutes a strong tool for understanding the relationships between microstructure and dielectric properties in this type of polymer composites.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7